Line a bin up for this regular event (8)
I believe the answer is:
biennial
'this regular event' is the definition.
Both the answer and definition are adjectives. Perhaps there's an association between them I don't understand?
'line a bin up' is the wordplay.
'up' indicates anagramming the letters (letters get chucked up).
'line'+'a'+'bin'='lineabin'
'lineabin' is an anagram of 'BIENNIAL'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for biennial that I've seen before include "Plant with a two-year life cycle" , "Happening every second year" , "Plant living two years" , "Taking place every other year" , "Two-yearly" .)