Assume German cheers after eliminating resistance (5)
I believe the answer is:
posit
'assume' is the definition.
(I know that posit is a more specific form of the action presuppose)
'german cheers after eliminating resistance' is the wordplay.
'german cheers' becomes 'prosit' (German word used when raising a toast).
'after eliminating' suggests deleting specific letters.
'resistance' becomes 'r' (electronics abbreviation).
'prosit' with 'r' taken out is 'POSIT'.
(Other definitions for posit that I've seen before include "Put forward (a theory)" , "Put forward (argument)" , "given proposition" , "advance" , "Propose" .)