before vowels pyel-, medical word-forming element used from mid-19c. in forming medical terms, from Greek pyelos "oblong trough, bathing-tub," a word of uncertain etymology, taken in modern scientific use for "pelvis."

plural of meninx, 1610s, "one of the three membranes enveloping the brain and spinal cord," from French meninges (1530s) or directly from medical Latin meninx, from Greek meninx (genitive meningos) "membrane," in medical Latin especially that of the brain (see member).

"inflammation of the mammary gland," 1842, medical Latin, from masto- "female breast" + -itis "inflammation."

short for venereal disease (see venereal), by 1916 in medical publications.

"muscular weakness," 1856, medical Latin; see myo- "muscle" + asthenia "weakness." Related: Myasthenic.

"the medical science of the eye and its functions and diseases," 1822; see ophthalmo- + -logy. Related: Ophthalmological.