Heave up out of wells, possibly (5)
I believe the answer is:
swell
'heave up' is the definition.
'swell' can be an answer for 'heave' (thesaurus). I'm unsure of the 'up' bit.
'wells possibly' is the wordplay.
'possibly' indicates anagramming the letters.
'wells' is an anagram of 'SWELL'.
'out of' acts as a link.
Can you help me to learn more?
(Other definitions for swell that I've seen before include "Excellent (slang)" , "VIP?" , "mushroom" , "Inflate - fine" , "Enlarge; excellent" .)