Like I'm surrounded by terrible liars (7)
I believe the answer is:
similar
'like' is the definition.
(synonyms)
'i'm surrounded by terrible liars' is the wordplay.
'surrounded by' means one lot of letters goes inside another.
'terrible' indicates anagramming the letters.
'liars' with letters rearranged gives 'silar'.
'im' put inside 'silar' is 'SIMILAR'.
(Other definitions for similar that I've seen before include "Of the same kind" , "Appearing the same" , "Akin" , "Resembling, like" , "Comparable" .)