Seldom (6)
'seldom' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for rarely that I've seen before include "once in a blue moon" , "Not very often, seldom in fact" , "Hardly ever, most infrequently" , "Very occasionally" , "Seldom, not frequently" .)
'seldom' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for rare that I've seen before include "Unusual - exquisite" , "difficult to find?" , "Not found often" , "having few matches?" , "Very lightly cooked, meat say" .)