Bright, lively (3)
I believe the answer is:
gay
I believe this is a double definition.
'bright' is the first definition.
(thesaurus)
'lively' is the second definition.
(similar in meaning)
(Other definitions for gay that I've seen before include "Light-hearted, carefree" , "John --, author of 'The Beggar's Opera'" , "Merry" , "Writer of The Beggar's Opera" , "Homosexual" .)