"containing or resembling slime or mucus," 1640s (replacing mucilaginous), from Latin mucosus "slimy, mucous," from mucus (see mucus). Related: mucosity.
1640s, in animal physiology, "act of preparing and expressing substances by glandular activity;" 1732 as "that which is secreted," from French sécrétion, from Latin secretionem (nominative secretio) "a dividing, separation," noun of action from past participle stem of secernere "to separate, set apart" (see secret (n.)).
"mucous, slimy, covered with mucus," 1731, from Latin mucosus (see mucous). Related: Mucosity (1680s).
"produce, prepare, or elaborate by process of secretion," 1707 (implied in secreted), a back-formation from secretion. Related: Secretes; secreting; secretious.