Curious saint having to wander (7)
I believe the answer is:
strange
'curious' is the definition.
(synonyms)
'saint having to wander' is the wordplay.
'saint' becomes 'st' (abbreviation).
'having' means one lot of letters go next to another.
'to wander' becomes 'range' (synonyms).
'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" .)