The Collaborative International Dictionary of English v.0.48:
Osculant \Os"cu*lant\, a. [L. osculans, -antis, p. pr. of
osculari to kiss. See Osculate.]
1. Kissing; hence, meeting; clinging.
2. (Zool.) Adhering closely; embracing; -- applied to certain
creeping animals, as caterpillars.
3. (Biol.) Intermediate in character, or on the border,
between two genera, groups, families, etc., of animals or
plants, and partaking somewhat of the characters of each,
thus forming a connecting link; interosculant; as, the
genera by which two families approximate are called