Time to perform outside, one implied (5)
I believe the answer is:
tacit
'implied' is the definition.
(synonyms)
'time to perform outside one' is the wordplay.
'time' becomes 't' (abbreviation).
'to perform' becomes 'act' (acting is a kind of performing).
'outside' is an insertion indicator (some letters go outside others).
'one' becomes 'i' (Roman numeral).
'act' going around 'i' is 'acit'.
't'+'acit'='TACIT'
(Other definitions for tacit that I've seen before include "Silently understood" , "Implied but not directly expressed" , "Implied without being stated" , "Silent - understood" , "Understood, not spoken or played" .)