Earthenware beer mug (5)
I believe the answer is:
stein
'earthenware beer mug' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for stein that I've seen before include "Gertrude ---; US writer" , "Earthenware beer jug" , "German tankard" , "Large earthenware beer mug" , "Gertrude __, avant-garde US author, d. 1946" .)