(1):

(n.) The act of suppressing, or the state of being suppressed; repression; as, the suppression of a riot, insurrection, or tumult; the suppression of truth, of reports, of evidence, and the like.

(2):

(n.) Omission; as, the suppression of a word.

(3):

(n.) Complete stoppage of a natural secretion or excretion; as, suppression of urine; - used in contradiction to retention, which signifies that the secretion or excretion is retained without expulsion.