Modioliform: globular, truncated at both ends; like the hub of a wheel.
Mola or Molar: the ridged or roughened grinding surface of the mandible: when the mandible is compound, the molar corresponds to the subgalea of maxilla.
Monarsenous: that kind of union where one male suffices for many females.
Moniliform: beaded like a necklace.
Monochromatic: of one color throughout.
Monodactyle: with a single movable claw which closes on the tip of the other leg structures as in some parasitica.
Monodomous: ants in which each colony has one nest only.
Monoecious: when both sexual elements or glands exist in one individual.
Monogamous: a union where a female is fertilized by one male only.
Monomeri: insects with one-jointed tarsi.