Bald-faced liars finally take note (6)
I believe the answer is:
shaven
'bald-faced' is the definition.
(without hair on the face)
'liars finally take note' is the wordplay.
'finally' suggests the final letters.
'take' becomes 'have' (synonyms).
'note' becomes 'n' (abbreviation).
The final letter of 'liars' is 's'.
's'+'have'+'n'='SHAVEN'
(Other definitions for shaven that I've seen before include "without locks" , "Hairless after work with razor" , "Without a beard" , "lacking coverage" , "With hair removed (N, not D)" .)