Meaning: adj. Not genuine; false; not authentic. Normally associated with persons, behaviours and experiences rather than items.
Etymology: Contrary to popular belief (google the term for examples), this is in fact a word, and can be cited as far back as the 17th Century:
1675
R. Burthogge Cavsa
Dei 352 'A many false, supposititious, and ingenuine' Writings.
Source: Oxford English
Dictionary online.
The word can be made by attaching the prefix in- (a variant of
un-) to the existing word 'genuine', in parallel to in- + sincere, in- + compatible, in- +
valid and so on.
Although it may often be confused with 'ingenuous', this is a simple malapropism and does not affect the validity of the word.