Definify.com
Webster 1913 Edition
Riser
Ris′er
,Noun.
1.
One who rises;
as, an early
. riser
2.
(Arch.)
(a)
The upright piece of a step, from tread to tread.
Hence:
(b)
Any small upright face, as of a seat, platform, veranda, or the like.
3.
(Mining)
A shaft excavated from below upward.
Webster 1828 Edition
Riser
RI'SER
, n.1.
One that rises; as an early riser.2.
Among joiners, the upright board of a stair.