adjective
always used before a noun
used to refer to a person or thing that is not known, named, or specified
of an unspecified amount or number
of a fairly large amount or number
informal
a - used to express approval
b - used to express disapproval, disappointment, etc.
pronoun
an unspecified amount or number of people or things
and then some
informal :and more in addition to that
adverb
used to indicate that a number is approximate
to an unspecified amount or degree