(biochemistry) Any of a class of peptide hormones released by the pituitary gland that are involved in regulating the production of melanin.

(biochemistry) A polypeptide hormone that is released by the chief cells of the parathyroid glands and is involved in raising the levels of calcium ions in the blood.

(endocrinology) A hormone that is involved primarily in stimulating the release of another hormone.

(archaic) Something a child can ride as though on horseback; a hobby-horse.

(archaic) Astride; mounted on something as though on horseback.

(slang, euphemistic) Sexual intercourse.

(idiomatic) To introduce slyly, to sneak in, to subvert. / (computer security) To install a Trojan horse.

Alternative form of a camel is a horse designed by a committee

(radio) A microwave antenna consisting of an open waveguide of increasing size towards the aperture

A tree of the species Ostrya virginiana (American hophornbeam). / Its wood.