Become aware lies are false (7)
I believe the answer is:
realise
'become aware' is the definition.
(to realise something is to become aware of it)
'lies are false' is the wordplay.
'false' is an anagram indicator.
'lies'+'are'='liesare'
'liesare' anagrammed gives 'REALISE'.
(Other definitions for realise that I've seen before include "Come to understand - see liar (anag)" , "produce" , "Apprehend; see lair (anag.)" , "catch on" , "Tumble" .)