After cycling endlessly, I dress for the beach (6)
I believe the answer is:
bikini
'the beach' is the definition.
(I've seen this before)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for bikini that I've seen before include "Infamous atoll" , "Kind of swimsuit" , "Pacific island - swimming costume" , "revealing clothing" , "offering scanty cover" .)