• Webster's Revised Unabridged Dictionary
    • n Osculum (Zoöl) Same as Oscule.
    • ***
Century Dictionary and Cyclopedia
    • n osculum In sponges, a mouth or principal exhalent aperture; one of the orifices by which water is expelled. See cuts under Porifera and Spongilla.
    • n osculum One of the suckers, bothria, or fossettes on the head of a tapeworm, by means of which the animal attaches itself to its host.
    • n osculum A pax: apparently an erroneous abbreviation for osculatorium.
    • ***
Chambers's Twentieth Century Dictionary
    • Osculum a mouth in sponges: one of the suckers on the head of a tapeworm
    • ***


Webster's Revised Unabridged Dictionary
L., a little mouth
Chambers's Twentieth Century Dictionary
L. osculāri, -ātusosculum, a little mouth, a kiss, dim. of os, mouth.


In literature:

Osculum ut phylangium inficit.
"The Anatomy of Melancholy" by Democritus Junior
A=pores; B=subdermal cavity; C=inhalent canal; D=ciliated chamber; E=exhalent canal; F=osculum; G=dermal membrane; H=eggs; J=gemmule.
"Freshwater Sponges, Hydroids & Polyzoa" by Nelson Annandale
The terminal osculum and lateral pores are represented as oval white spaces.
"The Works of Francis Maitland Balfour, Volume 1" by Francis Maitland Balfour