Son of Welsh prince to wander, OK? (7)
I believe the answer is:
approve
'ok?' is the definition.
(to OK something is to approve it)
'son of welsh prince to wander' is the wordplay.
'son of welsh' becomes 'ap' (I've seen this in other clues).
'prince' becomes 'p' (abbreviation).
'to wander' becomes 'rove' ('rove' can be a synonym of 'wander').
'ap'+'p'+'rove'='APPROVE'
(Other definitions for approve that I've seen before include "Agree" , "Give the go-ahead" , "Sanction, authorise" , "Officially accept as satisfactory" , "Give the green light" .)