Acting out lies deviously with hand signals? (13)
I believe the answer is:
gesticulation
'hand signals?' is the definition.
(hand signals are gestures or gesticulations)
'acting out lies deviously' is the wordplay.
'deviously' indicates an anagram (I've seen this in other clues).
'acting'+'out'+'lies'='actingoutlies'
'actingoutlies' is an anagram of 'GESTICULATION'.
'with' acts as a link.
(Other definitions for gesticulation that I've seen before include "Hand-waving" , "The adding of emphasis by moving arms or hands" , "Hand signal?" , "Hand signalling" .)