This is not one of the names of the Messenger (peace and blessings of Allaah be upon him)
Question

                I have baby girl we chosen the name MAHIN some peoples says its name of Prophet Mohammed (peace and blessings of Allaah be upon him) some says its other meaning kindly tell us exact meaning of this name.
Praise be to Allah.
    Firstly: 

    The scholars strove to compile all the names of the Prophet 
     (peace and blessings of Allaah be upon him) that are mentioned in the 
    Qur’aan, Sunnah and reports, but they differed concerning that.  Ibn Katheer 
    (may Allaah have mercy on him) said: 

    There are many ahaadeeth about that – i.e., the names of the 
    Prophet  (peace and blessings of Allaah be upon him) – and the two great 
    Haafizes Abu Bakr al-Bayhaqi and Abu’l-Qaasim ibn ‘Asaakir strove to collect 
    them, and people wrote books on this topic, until some of them wanted to 
    compile one thousand names of the Prophet  (peace and blessings of 
    Allaah be upon him). The great faqeeh Abu Bakr ibn al-‘Arabi al-Maaliki, who 
    wrote a commentary on al-Tirmidhi called al-Ahwadhi, compiled 
    sixty-four names. 

    Al-Bidaayah wa’l-Nihaayah 
    (2/252). 

    Ibn al-Qayyim (may Allaah have mercy on him) said: 

    The names of the Prophet  (peace and blessings of Allaah 
    be upon him) are of two types: 

    1 – Unique names that he did not share with any other 
    Messenger, such as Muhammad, Ahmad, al-‘Aaqib (the 
    successor, i.e., the one who succeeds the other Prophets in bringing about 
    good, or the Last Prophet), al-Haashir (the Gatherer), 
    al-Muqaffa (the last Prophet, following in their footsteps) and Nabi 
    al-Malhamah (the Prophet of Jihad). 

    2 – Names whose meanings he shared with other Messengers, but 
    he attained perfection therein, and he is the only one who attained 
    perfection but he was not the only one who attained these qualities, such as 
    Messenger of Allaah, Prophet of Allaah, slave of Allaah, al-Shaahid 
    (witness), al-Mubashshir (bringer of glad tidings), al-Nadheer (warner), 
    Nabi al-Rahmah (Prophet of Mercy), and Nabi al-Tawbah (Prophet of 
    repentance).  

    But if he is given a name for every one of his attributes, 
    the number of his names passes two hundred, such as al-Saadiq (the 
    Truthful), al-Masdooq (the one who is believed), al-Ra’oof (kind), al-Raheem 
    (compassionate) and so on. Concerning this some people said: Allaah has one 
    thousand names and the Prophet  (peace and blessings of Allaah be upon 
    him) has one thousand names. This was said by Abu’l-Khattaab ibn Dihyah, but 
    what he was referring to was his attributes. 

    Zaad al-Ma’aad (1/86). 

    Secondly: 

    After looking for these names, the scholars compiled them, 
    but we could not find among them the name mentioned by the questioner, 
    namely Maheen. Rather it is not possible for this name to be one of the 
    names of the Prophet  (peace and blessings of Allaah be upon him), 
    because its meaning is not befitting for the status of a Prophet and 
    Messenger. 

    Ibn Faaris (may Allaah have mercy on him) said: 

    Maheen means despicable or vile. 

    Mu’jam Maqaayees al-Lughah 
    (5/227). 

    Thirdly: 

    Perhaps the questioner has altered the name al-Muhaymin to 
    al-Maheen. Some scholars listed the former as one of the names of the 
    Prophet  (peace and blessings of Allaah be upon him), and in some books 
    it is miscopied as al-Maheen, but this is a grievous error.  

    Those who included the name al-Muhaymin among the names of 
    the Prophet  (peace and blessings of Allaah be upon him) quoted as 
    evidence the verse (interpretation of the meaning): “And We have sent 
    down to you (O Muhammad صلى الله عليه وسلم) 
    the Book (this Qur’aan) in truth, confirming the Scripture that came before 
    it and Muhaymin (trustworthy in highness and a witness) over it (old 
    Scriptures)” [al-Maa’idah 5:48].  

    But the majority of mufassireen are of the view that the word 
    muhaymin in this verse refers to the Book, i.e., the Qur’aan, and it is not 
    a description of the Prophet Muhammad  (peace and blessings of Allaah be 
    upon him). 

    Ibn Katheer (may Allaah have mercy on him), in his commentary 
    on the phrase “Muhaymin (trustworthy in highness and a witness) over it 
    (old Scriptures)”, mentioned three views held by the salaf: that it mean 
    al-Ameen (the one who entrusted with it), al-Shaahid (the one who bears 
    witness) and al-Haakim (the one who rules concerning its validity), then he 
    said:   

    These views are all close in meaning, and the word 
    al-muhaymin includes them all. So it is trustee, a witness and a judge over 
    every Book that came before it. 

    As for that which was narrated by Ibn Abi Haatim from 
    ‘Ikrimah, Sa’eed ibn Jubayr, ‘Ata’ al-Khurasaani and Ibn Abi Nujayh from 
    Mujaahid, that they said that the verse “Muhaymin (trustworthy in 
    highness and a witness) over it (old Scriptures)” referred to Muhammad 
     (peace and blessings of Allaah be upon him), who was entrusted with the 
    Qur’aan, it is correct in the sense that the Prophet  (peace and 
    blessings of Allaah be upon him) was entrusted with the Qur’aan but 
    interpreting the verse in this way needs to be examined further. So to sum 
    up, the former meaning is the correct one. 

    Abu Ja’far ibn Jareer said, after narrating it from Mujaahid: 
    This interpretation is far fetched with regard to Arabic language; in fact 
    it is incorrect, because al-muhaymin is mentioned in conjunction with 
    al-musaddiq (translated here as ‘confirming’), so it can only refer to that 
    to which al-musaddiq refers.  

    Tafseer Ibn Katheer (3/128). 

    Fourthly: 

    Our advice to you is to avoid both names: 

    Al-Muhaymin because it is also one of the names of Allaah, 
    may He be exalted, and it is not permissible to give people names that 
    belong only to Allaah. 

    Ibn al-Qayyim (may Allaah have mercy on him) said: 

    Among the names that it is forbidden to give to people are 
    the names of the Lord, may He be blessed and exalted. End quote. 

    Tuhfat al-Mawdood (120). 

    The same applies to the name al-Maheen, because it carries 
    meanings of humiliation, lowness and insignificance, and the Muslim is proud 
    of his Islam, noble in his faith. The Prophet  (peace and blessings of 
    Allaah be upon him) encouraged us to choose good names in the hope that 
    their owners would attain the noble attributes referred to thereby. 

    Ibn al-Qayyim (may Allaah have mercy on him) said: Rarely do 
    you see an ugly name but the one who is given it is ugly or bad. Allaah in 
    His wisdom has decreed that people will be inspired to give names that befit 
    the object named.  

    The Prophet  (peace and blessings of Allaah be upon him) 
    said: “May Allaah keep Aslam safe and sound (saalama) and may Allaah 
    forgive (ghafara) Ghifaar but ‘Usayyah have disobeyed Allaah and His 
    Messenger.” Agreed upon. These were Arab tribes whose names suited them. To 
    sum up, ugly attitudes and deeds dictate names that suit them. Just as that 
    applies to descriptions, it also applies to names of people. The Messenger 
    of Allaah  (peace and blessings of Allaah be upon him) was only called 
    Muhammad and Ahmad because of his many praiseworthy attributes. Hence the 
    banner of praise (al-hamd) will be in his hand and his ummah are those who 
    give praise, and he is the one who gives the most praise to his Lord. Hence 
    the Messenger of Allaah  (peace and blessings of Allaah be upon him) 
    enjoined giving good names, and he said: “Choose good names.” Narrated by 
    Abu Dawood but its isnaad is da’eef. The one who has a good name will feel 
    shy because of his name and his name may motivate him to do things that suit 
    it and avoid things that are contrary to it. Hence you see that most of 
    those who are vile have names that suit them, and most of those who are good 
    have names that suit them. And Allaah is the source of strength. End quote. 

    Tuhfat al-Mawdood (135). 

    See also the answers to questions no. 
    7180 and 
    1692. 

    And Allaah knows best.