We don't have synonyms for posser yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are posse, poser and poster.
(n) :
(UK) A tool for possing, or agitating laundry in a tub. It usually takes the form a bell shape or a circular plate with holes and vertical handle attached at the centre.
(n) :
(UK) A tool for possing, or agitating laundry in a tub. It usually takes the form a bell shape or a circular plate with holes and vertical handle attached at the centre.