Steer, behold, trapped in hole (5)
I believe the answer is:
pilot
'steer' is the definition.
(piloting is a kind of steering)
'behold trapped in hole' is the wordplay.
'behold' becomes 'lo'.
'trapped in' indicates putting letters inside.
'hole' becomes 'pit' (pit is a kind of hole**).
'lo' inserted into 'pit' is 'PILOT'.
(Other definitions for pilot that I've seen before include "Flier or helmsman" , "Aircraft captain" , "Person in charge of aircraft" , "Steer, test (scheme)" , "One who brings a vessel into port" .)