Singer has energy to celebrate (5)
I believe the answer is:
cheer
'celebrate' is the definition.
Although both the answer and definition are verbs in their base form, I don't understand how they can define each other.
'singer has energy' is the wordplay.
'singer' becomes 'cher' (American singer).
'has' is an insertion indicator.
'energy' becomes 'e' (physics symbol as in E=mch).
'cher' enclosing 'e' is 'CHEER'.
'to' is the link.
Can you help me to learn more?
(Other definitions for cheer that I've seen before include "Shout of approval" , "Perk up" , "Shout encouragingly" , "hurrah" , "one in three, perhaps" .)