Merriam-Webster Collegiate Dictionary - cyrus

 biographical name  424?-401 B.C. the Younger Persian prince & satrap CYST  noun  Etymology: New Latin ~is, from Greek kystis bladder, pouch; akin to Sanskrit svasiti he blows, snorts — more at wheeze  Date: circa 1720  1. a closed sac having a distinct membrane and developing abnormally in a cavity or structure of the body  2. a body resembling a ~: as  a. a resting spore of many algae  b. a gas-filled vesicle (as of a rockweed or bladderwort)  c. a capsule formed about a minute organism going into a resting or spore stage; also this capsule with its contents  d. a resistant cover about a parasite produced by the parasite or the host CYST  noun combining form  Etymology: New Latin ~is, from Greek kystis bladder ; sac blastocyst