Release final letter by fifth grader in suspension (6)
I believe the answer is:
freeze
'suspension' is the definition.
The definition and answer can be both acts as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'release final letter by fifth grader' is the wordplay.
'release' becomes 'free' (synonyms).
'final letter' becomes 'Z'.
'by' means one lot of letters go next to another.
'fifth grader' becomes 'e' (5th letter of 'grader').
'free'+'z'+'e'='FREEZE'
'in' is the link.
Can you help me to learn more?
(Other definitions for freeze that I've seen before include "Hold at fixed level - say prices" , "Harden into ice" , "Solidify due to decrease in temperature" , "Stand still!" , "Don't move!" .)