Cell  n. 1 small room, esp. In a prison or monastery. 2 small compartment, e.g. In a honeycomb. 3 small, active, esp. Subversive, political group. 4 a smallest structural and functional unit of living matter, consisting of cytoplasm and a nucleus enclosed in a membrane. B enclosed cavity in an organism etc. 5 vessel containing electrodes for current-generation or electrolysis. [latin cella]