A relative round to start refuge (5)
I believe the answer is:
oasis
'refuge' is the definition.
(I know that oasis is a type of harbor)
'a relative round to start' is the wordplay.
I cannot really see how this works, but
'a' is found in the answer.
'relative' could be 'sis' (short for sister) and 'sis' is found in the answer.
'round' could be 'o' (round can mean a round object) and 'o' is found within the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for oasis that I've seen before include "can provide welcome relief" , "Safe haven" , "Q-and-A game" , "water you'll want here" , "place of relief" .)