Met heretic helping to make theory rejected by Einstein (5)
I believe the answer is:
ether
'make theory rejected by einstein' is the definition.
I can't tell whether this definition defines the answer.
'met heretic helping' is the wordplay.
'helping' says the answer is hidden in the clue (a helping or portion of the letters).
'ETHER' is hidden in the letters of 'met heretic'.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for ether that I've seen before include "Old anaesthetic -- three (anag)" , "Colourless liquid used as a solvent" , "Medium supposedly" , "Gas - air - space" , "Volatile solvent" .)