English Vocabulary Flash Cards @ englishpdf.com and englishteststore.com File 185 duplicity (n) Double-dealing durance (n) Confinement duration (n) The period of time during which anything lasts duteous (adj) Showing submission to natural superiors dutiable (adj) Subject to a duty, especially a customs duty dutiful (adj) Obedient dwindle (v) To diminish or become less dyne (n) The force which, applied to a mass of one gram for second, would give it a velocity of cm/s