Word of the Day : May 28, 2019


noun luh-KOO-nuh


1 : a blank space or a missing part : gapalso : deficiency

2 : a small cavity, pit, or discontinuity in an anatomical structure

Did You Know?

Exploring the etymology of lacuna involves taking a plunge into the pit—or maybe a leap into the lacus (that's the Latin word for "lake"). Latin speakers modified lacus into lacuna and used it to mean "pit," "cleft," or "pool." English speakers borrowed the term in the 17th century. It is usually pluralized as lacunae; however, lacunas is an accepted variant plural. Another English word that traces its origin to lacuna is lagoon, which came to us by way of Italian and French.


The osteocyte is a cell that is isolated in a lacuna of bone.

"During her investigation, Charlie disguises herself as a man, but it's not entirely clear why the private detective does this—the only lacuna in an otherwise well-handled plot." — Eve Ottenberg, The Washington (D.C.) City Paper, 8 Apr. 2019

Test Your Vocabulary

What Latin-derived, 5-letter word beginning with "c" and ending with "m" refers to a cavity having but one opening?



More Words of the Day

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!