Summertime is the warmest season of the year. In the summertime, a summertime evening, the summertime crowds.
It is warmer and more evocative than summer alone, which is why songs prefer it. In Britain, British Summer Time is the clock setting rather than the season, so summertime and summer time mean different things by one space.
1nounsummertimeThe warmest season of the year.
“In summertime we eat outside in the garden almost every evening.”
summertime is a season.
Summer plus time, recorded in Middle English, with the same compound in Dutch and German.
Middle English
somertime
English, today
summertime
From Middle English somertime, equivalent to summer + time. Compare Dutch zomertijd (“summertime”), German Sommerzeit (“summertime”), Danish sommertiden (“summertime”), Swedish sommartid (“summertime”). Compare summertide.
Etymology from Wiktionary, CC BY-SA