She leans out to grab one (6)
I believe the answer is:
selina
'she' is the definition.
'leans out to grab one' is the wordplay.
'out' is an anagram indicator (out can mean wrong or inaccurate).
'to grab' indicates putting letters inside.
'one' becomes 'i' (roman numeral).
'leans' is an anagram of 'selna'.
'selna' going around 'i' is 'SELINA'.
(Other definitions for selina that I've seen before include "A woman" , "Girl" .)