Series of changes demanding energy on bike? (4,5)
I believe the answer is:
life cycle
'series of changes' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'energy on bike?' is the wordplay.
'energy' becomes 'life' (I've seen this in another clue).
'on' means one lot of letters go next to another.
'bike?' becomes 'cycle' ('cycle' can be a synonym of 'bike').
'life'+'cycle'='LIFE CYCLE'
'demanding' acts as a link.
Can you help me to learn more?
(Other definitions for life cycle that I've seen before include "(In biology) series of changes in form that an organism undergoes" , "our generation" , "Process eg from egg to imago to egg ..." , "Stages in development" , "Round of changes" .)