ˈakrəˌtärk noun
( -s )
Etymology: Greek akrit os confused, uncertain (from a- a- (II) + kritos , verbal of krinein to separate, decide) + archē beginning — more at certain archi-
: any of a group of fossil one-celled marine planktonic organisms of uncertain and possibly various taxonomic affinities that are held to represent the earliest known eukaryotes