Seeds consumed by extinct primates with the close of biggest peace offering (11)
I believe the answer is:
appeasement
'biggest peace offering' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'seeds consumed by extinct primates with the close of' is the wordplay.
'seeds' becomes 'peas' (I have seen 'Edible seeds ' mean 'peas' so perhaps 'seeds' could also mean 'peas').
'consumed by' indicates putting letters inside.
'extinct primates' becomes 'apemen' (I've seen this before).
'with' says to put letters next to each other.
'the close of' becomes 't' (I can't justify this - if you can you should believe this answer much more).
'peas' going into 'apemen' is 'appeasemen'.
'appeasemen'+'t'='APPEASEMENT'
Can you help me to learn more?
(Other definitions for appeasement that I've seen before include "Act of placating by making concessions" , "Action of placating by making concessions" , "Action of placating somebody" , "Placation" , "Offer of concessions" .)