Female with one book that's not true (3)
I believe the answer is:
fib
'not true' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'female with one book' is the wordplay.
'female' becomes 'f' (common abbreviation).
'with' is a charade indicator (letters next to each other).
'one' becomes 'i' (Roman numeral).
'book' becomes 'b' (abbreviation for book).
'f'+'i'+'b'='FIB'
'that's' is the link.
Can you help me to learn more?
(Other definitions for fib that I've seen before include "One must be 20 [UNTRUE]" , "Small lie" , "Little white lie" , "minor piece of fiction" , "Story" .)