Pledge to eat diced concoction (8)
I believe the answer is:
dedicate
'pledge' is the definition.
(I've seen this in another clue)
'eat diced concoction' is the wordplay.
'concoction' indicates an anagram.
'eat'+'diced'='eatdiced'
'eatdiced' with letters rearranged gives 'DEDICATE'.
'to' is the link.
(Other definitions for dedicate that I've seen before include "Devote (to), pledge (to)" , "Commit" , "Devote to a sacred person or use" , "Devote to a special purpose, say time or energy" , "Inscribe or give over to" .)