Endlessly striving for better pain relief (7)
I believe the answer is:
aspirin
'better pain relief' is the definition.
'aspirin' can be an answer for 'relief' (I have seen 'Pain relief' mean 'aspirin' so perhaps 'relief' could also mean 'aspirin'). I also know that 'pain' relates to this answer.
'endlessly striving' is the wordplay.
'endlessly' means to remove the last letter.
'striving' becomes 'aspiring' (I've seen this before).
'aspiring' with its final letter taken away is 'ASPIRIN'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for aspirin that I've seen before include "Headache killer?" , "Common painkiller" , "Anti-inflammatory tablet" , "Headache pill" , "Common drug in Paris" .)