Speak one's piece, let's suppose? (3)
I believe the answer is:
say
I believe this clue is a triple definition!
'speak one's piece' is the first definition.
'say' can be an answer for 'speak' (I've seen this before). I am not certain of the 'one's piece' bit.
'let's' is the second definition.
(thesaurus)
'suppose?' is the third definition.
(I know that suppose can be written as say)
Can you help me to learn more?
(Other definitions for say that I've seen before include "Speak, declare" , "Utter words" , "Tell" , "Let us suppose" , "Utter, recite" .)