English Vocabulary Flash Cards @ englishpdf.com and englishteststore.com File 184 drowsy (adj) Heavy with sleepiness drudgery (n) Hard and constant work in any menial or dull occupation dubious (adj) Doubtful duckling (n) A young duck ductile (adj) Capable of being drawn out, as into wire or a thread duet (n) A composition for two voices or instruments dun (v) To make a demand or repeated demands on for payment duplex (adj) Having two parts