ˌ ̷ ̷ ̷ ̷ˈsistə̇s noun
Usage: capitalized
Etymology: New Latin, from micr- + -cystis
: a genus of unicellular blue-green algae (family Chroococcaceae) forming irregularly shaped colonies within a common gelatinous envelope and including at least one species ( M. aeruginosa ) that is poisonous and may become abundant and troublesome in lakes especially where much organic matter is present