- past of|classify
#:Make sure all the field observations are classified by species.
- National security information formally assigned by governments to one of several levels of sensitivity, usually (in English) top secret, secret, confidential, and, in some countries, restricted; thereby making disclosure to unauthorized persons illegal.
#:We do not discuss specific interrogation techniques because they are classified information.
#Any information a person or organization does not wish to disclose.
#:I won't say who I'm going to the prom with; that's classified.
- informal A classified advertisement in a newspaper or magazine.
#: He ran a classified for the tools he wanted to sell.