Definition of quadruples:
(adj) :
Being four times as long, as big or as many of something.
(v) :
(transitive) To multiply by four.
(v) :
(intransitive) To increase by a factor of four.
(n) :
Something that is four times the usual number, amount, size, etc.
(n) :
(skating) A figure-skating jump with four revolutions in the air.
(v) :
(rail transport) To provide four parallel running lines on a given stretch of railway.