Acquiesce (to) (6)
(Other definitions for assent that I've seen before include "Agree - concede" , "Compliance, agreement" , "Expression of agreement" , "Acquiescence" , "Permit or approve" .)
(Other definitions for accede that I've seen before include "Comply" , "Say yes to request" , "Yield" , "Allow, acquiesce" , "Assume" .)