Curious saint having to wander (7)
I believe the answer is:
strange
'curious' is the definition.
(similar in meaning)
'saint having to wander' is the wordplay.
'saint' becomes 'st' (abbreviation).
'having' says to put letters next to each other.
'to wander' becomes 'range' ('range' can be a synonym of 'wander').
'st'+'range'='STRANGE'
(Other definitions for strange that I've seen before include "Unusual, odd" , "Odd, peculiar" , "Extraordinary" , "Peculiar; Morse's boss" , "Odd or unfamiliar" .)