Origins
The use of "spring" for the season between winter and summer is a relatively recent development in the history of English, dating only to the 14th century. Unlike "summer" and "winter," which are among the oldest words in the language, "spring" as a season name is a metaphorical extension of the verb "to spring" — to leap, burst forth, or grow. The full story of how this word came to name a season involves the displacement of an older term and a vivid agricultural metaphor.
The verb springan in Old English meant "to leap, jump, burst forth, sprout, or grow." It descended from Proto-Germanic *springaną, which is the source of German springen and Dutch springen (both meaning "to jump"). The deeper PIE root is reconstructed as *sprenǵʰ-, meaning "to move quickly" or "to spring." The verb's semantic range in Old English was wide: water could spring from the ground (hence "spring" as a water source), warriors could spring into action, and plants could spring from the soil.
It was this last sense — the springing of vegetation — that gave rise to the season name. In the 14th century, the phrase "springing time" or "spring of the year" began to appear in English texts, referring to the time when plants spring up from the earth after winter dormancy. By the 16th century, the phrase had been shortened to simply "spring," and this became the standard name for the season.
Old English Period
Before "spring" took over, the season had a different name in English. Old English used lencten (from a Germanic root meaning "long" or "lengthening"), referring to the lengthening of days as the sun climbed higher after the winter solstice. German still uses a descendant of this word — Lenz is an archaic or poetic term for spring. In English, however, lencten was gradually absorbed into the ecclesiastical calendar as "Lent," the Christian period of fasting before Easter. As the word became primarily associated with the religious observance, a gap opened in the secular vocabulary, and "spring" filled it.
The pattern of naming a season after plant growth is not unique to English, but it is relatively uncommon among European languages. French printemps comes from Latin prīmum tempus ("first time" or "first season"). German Frühling derives from früh ("early"). Italian primavera comes from Latin prīma vēra ("first spring/truth of the year"). English stands somewhat apart in grounding its season name in a concrete physical image — the visible springing of plants from the ground.
The word "spring" thus illustrates a phenomenon that linguists call polysemy through metaphorical extension. A single verb meaning "to leap" produced, over centuries, nouns for a water source (where water leaps from the ground), a coiled device that stores energy (which springs back when released), the season of plant growth (when vegetation springs forth), and numerous figurative uses (the spring of hope, the spring of youth). Each meaning preserves a different facet of the original concept of sudden, energetic emergence.
Cultural Impact
The compound "offspring" is a related and venerable derivative — from Old English ofspring, meaning "that which springs from" a person, i.e., their children or descendants. "Wellspring," meaning an abundant source, combines "spring" (water source) with "well" for emphasis. "Springboard" and "springtime" are later formations that continue the word's productive history.
In naming its season of renewal after the simple, observable act of plants bursting from the soil, English chose a word of earthy directness — a fitting name for the time of year when the natural world reasserts itself after the stillness of winter.