Arsenal player given a giant rhubarb (7)
I believe the answer is:
gunnera
'a giant rhubarb' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.
'arsenal player' is the wordplay.
I cannot quite see how this works, but
'arsenal' could be 'ra' (Royal Artillery) and 'ra' is present in the answer.
'player' could be 'e' (I've seen this in other clues) and 'e' is present in the answer.
The remaining letters 'gunn' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'given' acts as a link.
Can you help me to learn more?
(Other definitions for gunnera that I've seen before include "Waterside plant with very large leaves" , "It grows" , "Very large-leaved shrub" , "Large-leaved plant" .)