What is "crypto-"

before vowels crypt-, word-forming element meaning "secret" or "hidden," used in forming English words since at least 1760, from Latinized form of Greek kryptos "hidden, concealed, secret" (see crypt; the Greek comb. form was krypho-). Crypto-fascist is attested from 1937; crypto-communist from 1946.

pre. 1 hidden, invisible 2 secret.