Lass with large insect is brave (7)
I believe the answer is:
gallant
'brave' is the definition.
(similar in meaning)
'lass with large insect' is the wordplay.
'lass' becomes 'gal' (both can mean a girl).
'with' is a charade indicator (letters next to each other).
'large' becomes 'L' (eg in clothes sizes).
'insect' becomes 'ant' (ant is a kind of insect).
'gal'+'l'+'ant'='GALLANT'
'is' is the link.
(Other definitions for gallant that I've seen before include "Brave; courteous" , "lover" , "Courageous - politely attentive to women" , "Heroic; chivalrous" , "Dashing, debonair young man" .)