What's the "een" in Halloween?
1902, from cryogen "freezing mixture" (1875), from cryo- "freezing" + -genic "having to do with production" (see genus). Related: Cryogenics (1958).
cryogenic cry·o·gen·ic (krī'ə-jěn'ĭk)adj.
Relating to or producing low temperatures.
Requiring or suitable for storage at low temperatures.