Plastic beer mugs in sink (8)
I believe the answer is:
submerge
'sink' is the definition.
(submerging is a kind of sinking)
'plastic beer mugs' is the wordplay.
'plastic' indicates anagramming the letters (plastic can mean easily moulded).
'beer'+'mugs'='beermugs'
'beermugs' is an anagram of 'SUBMERGE'.
'in' acts as a link.
(Other definitions for submerge that I've seen before include "Put under liquid's surface" , "Disappear below surface" , "Sink - inundate" , "Put under water" , "(Submarine) dive" .)