Definify.com
Webster 1913 Edition
Seasonal
Sea′son-al
,Adj.
1.
Of or pertaining to the seasons.
2.
Occurring or being used in a specific season;
as,
. seasonal
items for saleSeasonal dimorphism
(Zool.)
, the condition of having two distinct varieties which appear at different seasons, as certain species of butterflies in which the spring brood differs from the summer or autumnal brood.