Synonyms for Buttery (same or very similar meaning)
WordNet sense 1 (a small storeroom for storing foods or wines):
larder, pantry
WordNet sense 2 (unpleasantly and excessively suave or ingratiating in manner or speech):
fulsome, oily, oleaginous, smarmy, soapy, unctuous
WordNet sense 3 (lacking sincerity):
insincere
WordNet sense 4 (containing or composed of fat):
fat, fatty
From the ODE community, based on WordNet
add/edit