mid-14c., "the part of man that is concerned with the senses," from O.Fr. sensualité, from L.L. sensualitatem (nom. sensualitas) "capacity for sensation," from L. sensualis "endowed with feeling, sensitive," from sensus "feeling" (see sense). Chiefly "animal instincts and appetites," hence "the lower nature regarded as a source of evil, lusts of the flesh" (1620s).
mid-15c., "of or pertaining to the senses," from L.L. sensualis (see sensuality). Meaning "connected with gratification of the senses," especially "lewd, unchaste" is attested from late 15c.