Bit of a stare from Jack (3)
I believe the answer is:
tar
'jack' is the definition.
(both are informal terms for sailor)
'bit of a stare from' is the wordplay.
'bit of' says the answer is hidden in the clue.
'TAR' can be found hidden inside 'stare from'.
(Other definitions for tar that I've seen before include "It may cover the road" , "Naval man" , "Liquid from wood, coal" , "Road-making substance" , "Product of coal" .)