Many admit to being inexperienced (6)
I believe the answer is:
callow
'being inexperienced' is the definition.
(synonyms)
'many admit' is the wordplay.
'many' becomes 'c' (C is the Roman numeral for 100).
'admit' becomes 'allow' (allowing is a kind of admiting).
'c'+'allow'='CALLOW'
'to' acts as a link.
(Other definitions for callow that I've seen before include "Green" , "Simon ---, actor; immature" , "Inexperienced or unsophisticated, as a youth say" , "lacking experience of life" , "Immature and inexperienced, like youth" .)