Heartless weirdo, brawny, topless and dim (11)

'dim' is the definition.
Both the answer and definition are adjectives. Maybe you can see a link between them that I don't see?

'heartless weirdo brawny topless' is the wordplay.
'heartless' says to hollow out the word (remove centre letters).
'weirdo' becomes 'creep' ('creep' can be a synonym of 'weirdo').
'brawny' becomes 'muscular' ('muscular' can be a synonym of 'brawny').
'topless' means to remove the first letter.
'creep' with its centre taken out is 'crep'.
'muscular' with its initial letter taken away is 'uscular'.
'crep'+'uscular'='CREPUSCULAR'

'and' is the link.

Can you help me to learn more?