unpronounceable adjective 1noun 1forms 3 adjective1 •Impossible or difficult to pronounce or articulate. noun1 •Something, especially an ingredient, that is difficult or impossible to pronounce.Synthetic fragrances can contain a laundry list of chemicals — hormone disrupters, petroleum-derived unpronounceables, asthma triggers and on and on. — 2009 formsunpronounceables · more unpronounceable · most unpronounceable