sum·mer 1 
(sŭmər)
(sŭmər)n.
1.
a. In the Northern Hemisphere, the usually warmest season of the year, occurring between spring and autumn and constituting June, July, and August. In the Southern Hemisphere, it constitutes December, January, and February.
b. The season extending from the summer solstice to the autumnal equinox.
2. A period of fruition, fulfillment, happiness, or beauty.
3. A year: a girl of 13 summers.
v. sum·mered, sum·mer·ing, sum·mers
v.tr.
To lodge or keep during the summer: summered the herd in the south meadow.
v.intr.
To pass the summer: They summered at a beach resort.
adj.
1. Relating to or occurring in summer: summer heat; summer attire.
2. Grown during the season of summer: summer crops.
[Middle English sumer, from Old English sumor; see sem-2 in the Appendix of Indo-European roots.]
summer·ly adv. & adj.