Not put one's finger on something - Idioms by The Free Dictionary
not put (one's) finger on (something) (redirected from not put one's finger on something)
not put (one's) finger on (something)
To not recall fully, clearly, or correctly. I can't put my finger on what this is reminding me of. There's something I was supposed to do this afternoon, but I can't put my finger on it.
not put your ˈfinger on something (informal) not be able to say exactly what is wrong or different about a particular situation: I knew something she had said wasn’t true, but I couldn’t quite put my finger on it. ♢ There’s something wrong with these statistics but I just can’t put my finger on what it is.