Stray, right after hesitation (3)
I believe the answer is:
err
'stray' is the definition.
('err' can be a synonym of 'stray')
'right after hesitation' is the wordplay.
'right' becomes 'r' (common abbreviation).
'after' means one lot of letters go next to another.
'hesitation' becomes 'er'.
'r' after 'er' is 'ERR'.
(Other definitions for err that I've seen before include "Blunder" , "'To . . . is human, to forgive divine'" , "Boob" , "Leave the straight and narrow" , "Sin" .)