■ adjective winding in a continuous and gradually widening (or tightening) curve around a central point or axis.
↘winding in a continuous curve of constant diameter about a central axis, as though along a cylinder; helical.
↘ Astronomy denoting galaxies in which the stars and gas clouds are concentrated mainly in ~ arms.
■ noun
1》 a ~ curve, shape, or pattern.
2》 a progressive rise or fall of prices, wages, etc., each responding to an upward or downward stimulus provided by a previous one.
↘a process of progressive deterioration.
■ verb ( ~s , ~ling , ~led ; US ~s , ~ing , ~ed )
1》 take or cause to follow a ~ course.
2》 show a continuous and dramatic increase.
↘( ~ down/downward ) decrease continuously.
Derivatives
~ly adverb
Origin
C16: from med. L. ~is , from L. spira (see spire 2 ).