heterocyst

[ het-er-uh-sist ]
/ ˈhɛt ər əˌsɪst /

noun Bacteriology.

one of the enlarged nitrogen-fixing cells occurring along the filaments in some blue-green algae.

Origin of heterocyst

First recorded in 1870–75; hetero- + cyst
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019