Found a sailor in the way (5)
I believe the answer is:
start
'found' is the definition.
(as in to establish)
'a sailor in the way' is the wordplay.
'a sailor' becomes 'tar' (term for a sailor).
'in the' means one lot of letters goes inside another.
'way' becomes 'st' (abbreviation for street).
'tar' going inside 'st' is 'START'.
(Other definitions for start that I've seen before include "Onset" , "Begin; flinch" , "Outset" , "Set in motion" , "Begin with sudden movement of surprise" .)