un pahar - a glass (n sg indef)
paharul - the glass (n sg def)
pahare - glasses (n pl indef)
paharele - the glasses (n pl def)
Un pahar cu vin. - a glass of wine
For drinking ! The word for spectacles (or eye-glasses) is ochelari (masculine gender) Words for a "monocle", are "monoclu" or (the 'frenchy') "lornion" (?) Opera glasses in French are "lorgnon" or "lorgnette" (plural).