Defn: Belonging to the Malacopterygii.

MALACOSTEON
Mal`a*cos"te*on, n. Etym: [NL., Gr. fr. (Med.)

Defn: A peculiar disease of the bones, in consequence of which they become softened and capable of being bent without breaking.

MALACOSTOMOUS
Mal`a*cos"to*mous, a. Etym: [Gr. (Zoöl.)

Defn: Having soft jaws without teeth, as certain fishes.

MALACOSTRACA
Mal`a*cos"tra*ca, n. pl. Etym: [NL., from Gr. (Zoöl.)

Defn: A subclass of Crustacea, including Arthrostraca and
Thoracostraca, or all those higher than the Entomostraca.

MALACOSTRACAN
Mal`a*cos"tra*can, n. (Zoöl.)

Defn: One of the Malacostraca.

MALACOSTRACOLOGY
Mal`a*cos`tra*col"o*gy, n. Etym: [Malacostracan + -logy.]