Muck, perhaps dissolves evenly? (4)
I believe the answer is:
isle
'muck' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.
'dissolves evenly?' is the wordplay.
'evenly?' means one should take alternating letters (I've seen 'evenly' mean this (the letters in even-numbered positions)).
The alternate letters of 'dissolves' are 'ISLE'.
'perhaps' acts as a link.
Can you help me to learn more?
(Other definitions for isle that I've seen before include "It lies badly in water" , "Fair ---, knitting style" , "Lies (anag)" , "Man, possibly" , "Dogs, maybe" .)