\ kē-ˌär-ə-ˈskyu̇r-(ˌ)ō \ Noun The treatment of light and shade in drawing and painting From Italian chiaro “light” + oscuro “dark” The artist’s use of chiaroscuro gave the painting a

\ ˈbäm-bə-ˌnāt \ Verb To make a humming or buzzing noise From Latin bombinatus, from bombinare “to buzz” The bees bombinated around the garden, busy collecting nectar.

\ ˈer-ə-ˌdīt \ Adjective Having or showing great knowledge or learning From Latin eruditus, past participle of erudire “to instruct” The professor was an erudite scholar, respected by all his

\ kwi-ˈzā-shəs \ Adjective Given to bantering or teasing Likely coined in the 19th century, from quiz + -acious His quizzacious remarks kept the mood light during the meeting.

\ i-ˈfe-mə-rəl \ Adjective Lasting for a very short time From Greek ephemeros “lasting only a day” The beauty of the sandcastle was ephemeral, as the tide soon washed it

\ sə-ˈsər-əs \ Noun Whispering, murmuring, or rustling From Latin susurrus “whisper” The susurrus of the leaves in the wind was calming.

\ ˌka-kə-ˈē-thēz \ Noun An irresistible urge to do something inadvisable From Greek kakos “bad” + ēthos “habit” His cacoethes for gambling eventually led to his downfall.

\ ˌin-i-fi-ˈkā-shəs \ Adjective Not producing the desired effect From Latin inefficax, from in- “not” + efficax “effectual” The medication was found to be inefficacious in treating the condition.

\ lə-ˈgü-brē-əs \ Adjective Looking or sounding sad and dismal From Latin lugubris “mournful,” from lugere “to mourn” The lugubrious music set the tone for the somber ceremony.

\ ˌir-ə-ˈde-sᵊnt \ Adjective Showing luminous colors that seem to change when seen from different angles From Latin iris, irid- “rainbow” The butterfly’s wings were iridescent in the sunlight.