- atom, molecule, particle, corpuscle, mote, speck - (nontechnical usage) a tiny piece of anything
--1 is a kind of material, stuff
--1 has particulars: grain; chylomicron; flyspeck - blood cell, blood corpuscle, corpuscle - either of two types of cells (erythrocytes and leukocytes) and sometimes including platelets
--2 is a kind of somatic cell, vegetative cell
--2 is a part of blood
--2 has particulars:leukocyte, leucocyte, white blood cell, white cell, white blood corpuscle, white corpuscle, WBC; packed cells; red blood cell, RBC, erythrocyte