'In season' definitions:

Definition of 'In season'

From: GCIDE

Season \Sea"son\, n. [OE. sesoun, F. saison, properly, the sowing time, fr. L. satio a sowing, a planting, fr. serere, satum, to sow, plant; akin to E. sow, v., to scatter, as seed.]
1. One of the divisions of the year, marked by alterations in the length of day and night, or by distinct conditions of temperature, moisture, etc., caused mainly by the relative position of the earth with respect to the sun. In the north temperate zone, four seasons, namely, spring, summer, autumn, and winter, are generally recognized. Some parts of the world have three seasons, -- the dry, the rainy, and the cold; other parts have but two, -- the dry and the rainy. [1913 Webster]
The several seasons of the year in their beauty. --Addison. [1913 Webster]
2. Hence, a period of time, especially as regards its fitness for anything contemplated or done; a suitable or convenient time; proper conjuncture; as, the season for planting; the season for rest. [1913 Webster]
The season, prime for sweetest scents and airs. --Milton. [1913 Webster]
3. A period of time not very long; a while; a time. [1913 Webster]
Thou shalt be blind, not seeing the sun for a season. --Acts xiii. 11. [1913 Webster]
4. That which gives relish; seasoning. [Obs.] [1913 Webster]
You lack the season of all natures, sleep. --Shak. [1913 Webster]
In season, in good time, or sufficiently early for the purpose.
Out of season, beyond or out of the proper time or the usual or appointed time. [1913 Webster]