Matrix (ma'trix). The womb. The groundwork in which anything is cast.

Meatus (me-a'tus). A passage or opening.

Medulla Oblongata (med-ul-lah oblong-at'-a). An organ or ganglion of the brain which connects the spinal cord with the pons.

Menses (men'sez). Monthly flow from the womb.

Menstrual (men'stru-al). Pertaining to menstruation.

Menstruum (men'stru-urn). A solvent.

Metastasis (met-as'tas-is). The transfer of a diseased process from a primary focus to a distance by the conveyance of the causal agents through the blood vessels or lymph channels, like mumps from face to the scrotum.

Metatarsus (met-ah-tar'-sus). The bones of the foot—situated between the (instep) tarsus and toes.

Miasm (mi'asm). Anything harmful contaminating the air.

Micturition (mik-tu-rish'-un). The act of passing urine.