Archaic

Rarely used today, except in certain restricted contexts, but occurs in earlier writings

Colloquial

In widespread use and is generally characteristic of conversation and informal writing

Historical

Refers to something that no longer exists and to which no term that is more current applies

Obsolete

No longer used but occurs in earlier writings

Old-fashioned

Not yet considered archaic but has the connotation of being spoken by an older generation of people

Rare

Not often used or has never been common

Slang

Not generally regarded as conventional or standard, but is used in highly informal contexts or for special effect

Register

A variety of language chosen by a user in a particular social context

Honorific

Used to confer honor or show respect

Nonstandard

A form that does not conform to the norm of speaking or the prestige dialect

Restrictive

Used only in certain limited contexts and may be highly inappropriate or offensive if used in other contexts