The first few are horrid (7)
I believe the answer is:
noisome
'horrid' is the definition.
(thesaurus)
'the first few' is the wordplay.
'the first' becomes 'noi' (I've seen this in other clues).
'few' becomes 'some' (associated in meaning).
'noi'+'some'='NOISOME'
'are' acts as a link.
(Other definitions for noisome that I've seen before include "Harmful to health; disgusting" , "Repugnant" , "Foul; putrid" , "Having an extremely offensive smell" , "Offensively smelly" .)