A prefix is an affix which is placed before the stem of a word. Adding it to the beginning of one word changes it into another word. For example, when the prefix un- is added to the word happy, it creates the word unhappy.
https://en.wikipedia.org/wiki/Prefix
Suffix used in anatomic nomenclature meaning -ward; toward or in the direction of the part indicated by the main portion of the word. -ad. In anatomic nomenclature, a suffix synonymous with -ward; toward or in the direction of the part indicated by the main portion of the word.
http://medical-dictionary.thefreedictionary.com/-ad
Suffix used in anatomic nomenclature meaning -ward; toward or in the direction of the part indicated by the main portion of the word. [L. ad, to] In anatomic nomenclature, a suffix synonymous with -ward; toward or in the direction of the part indicated by the main portion of the word. [L. ad, to]
http://medical-dictionary.thefreedictionary.com/-ad
a prefix meaning “toward,” “to,” “on,” “over,” “against,” originally occurring in loanwords from Latin, but now used also, with the sense of “reversely,” “inversely,” to form Neo-Latin and English scientific terms: object; obligate; oblanceolate. 1  Also, o-, oc-, of-, op-.
http://www.dictionary.com/browse/ob-
The word prefix is itself made up of the stem fix (meaning attach, in this case), and the prefix pre- (meaning before), both of which are derived from Latin roots. 1 In English 1.1 List of English derivational prefixes.
https://en.wikipedia.org/wiki/Prefix
prefix meaning toward, against, across, down, also used as an intensive, from Latin ob toward, to, over against, in the way of, by reason of, about, before, in front of, from PIE root *epi, also *opi near, against (see epi-).
http://www.dictionary.com/browse/ob-
Prefixes are key morphemes in English vocabulary that begin words. The prefix ad- means “to, towards;” today we will address increasing you vocabulary knowledge by looking “towards” this highly used prefix! When companies advertise their products, they are trying to turn your attention “towards” what they are selling.
http://membean.com/wrotds/ad-towards
Prefixes are key morphemes in English vocabulary that begin words. The English prefix ad- means “to, towards.” Examples using this prefix include admit and adjust. An easy way to remember that the prefix ad- means “towards” is through the word advertise, for when you advertise you try to turn potential buyers “towards” the product you are selling.
http://membean.com/wrotds/ad-towards
a prefix occurring in loanwords from Latin, where it meant “toward” and indicated direction, tendency, or addition: adjoin . Usually assimilated to the following consonant; see a-5 , ac-, af-, ag-, al-, an-2 , ap-1 , ar-, as-, at-. Origin of ad-.
http://www.dictionary.com/browse/ad-
a prefix occurring in loanwords from Latin, where it meant “toward” and indicated direction, tendency, or addition: adjoin . Usually assimilated to the following consonant; see a-5 , ac-, af-, ag-, al-, an-2 , ap-1 , ar-, as-, at-. ad-.
http://www.dictionary.com/browse/ad-
which prefix means toward
Ad is a prefix which means toward. AD is prefix that means Toward. The prefix Ad means toward.