Definition of "osis" [osis]

• A suffix of Greek origin in words signifying the act of making something so-and-so (equivalent to -ing, -ation, etc.), process, state, etc., as in anastomosis, orthosis, sphrigosis. In medical terms it often implies an abnormal or diseased condition, as in chlorosis, melanosis, necrosis, neurosis, stenosis, trichinosis, tuberculosis, etc. (noun)

The Century Dictionary (Public Domain)

• "All of the afflictions they pointed toward seemed to end in “osis.”"
• "One was a three-parter: What general meaning do each of these suffixes signify, - osis, - algia and - itis?"
• "Please, guys, don't simply hope your suit/sport jacket will hide your tie gap-osis."