A particle which expresses the relation of connection or addition. It is used to conjoin a word with a word, a clause with a clause, or a sentence with a sentence.
a useful or valuable quality
further or added; "called for additional troops"; "need extra help"; "an extra pair of shoes"
something additional of the same kind; "he always carried extras in case of an emergency"
more than is needed, desired, or required; "trying to lose excess weight"; "found some extra change lying on the dresser"; "yet another book on heraldry might be thought redundant"; "skills made redundant by technological advance"; "sleeping in the spare room"; "supernumerary ornamentation"; "it was supererogatory of her to gloat"; "delete superfluous (or unnecessary) words"; "extra ribs as well as other supernumerary internal parts"; "surplus cheese distributed to the needy"
an additional edition of a newspaper (usually to report a crisis)
added to a regular schedule; "a special holiday flight"; "put on special buses for the big game"