the.com/growth spurt

means A short, rapid burst of physical growth — especially in children and teens — where height, bones, or body size increase noticeably faster than usual.

from A fairly plain compound, not an ancient one. 'Growth' traces back to Old Norse 'grōa' (to grow, to flourish, used even of wounds healing), while 'spurt' originally meant a sudden jet or gush of liquid before the 19th century stretched it to cover any short, sharp burst of activity or effort. Jam the two together and you get a term that reads exactly as it sounds: growth behaving like a burst pipe rather than a steady drip.