It seems ironic to be defining the term 'dictionary,' but here we go! Dictionaries are resources for finding word meanings, parts of speech, word origins and even synonyms and antonyms. Dictionaries have definitely evolved over the years. The English language really began with the Anglo-Saxons in Great Britain.
If it is a US Passport, that it is the 9 digit number located in the top corner of the passport info page. In the example below the passport number is 31195855. Other Countries have different types of numbers (usually with letters added) but most often it's in the same place. This Canadian Passport number is AB504966.
This question has already been answered on Quora here: Where do I see the US visa number on a passport? The visa number of a United States visa is printed in red color (it is the only number in red on the visa) and is located in the lower right corner of the visa. It consists of eight letters and numbers. It is NOT the Control Number, which is something else. Written Dec 7, 2015.