ˈdīəˌtäm sometimes -əd.əm or -ətəm noun
( -s )
Etymology: New Latin Diatoma
: any of the unicellular or colonial algae constituting a class (Bacillariophyceae), having a silicified cell wall that persists as a skeleton after death and forms diatomite, and forming a large part of the plankton of both fresh and salt water — see frustule , girdle e(1), valve