Being agile he lit out (5)
I believe the answer is:
lithe
'being agile' is the definition.
(I've seen this before)
'he lit out' is the wordplay.
'out' is an anagram indicator (out can mean wrong or inaccurate).
'he'+'lit'='helit'
'helit' with letters rearranged gives 'LITHE'.
(Other definitions for lithe that I've seen before include "Supple and limber" , "Able to move and bend gracefully" , "showing flexibility" , "grace" , "Physically flexible or supple" .)