Crescendo
Etymology
Italian "crescendo," the present participle of "crescere" (to grow), from Latin "crescere" — the same root behind "crescent," "increase," and "accrue." It literally means "growing," a direction printed in a score.
noun · /kruh-SHEN-doh/
A gradual increase in loudness (and, loosely, in intensity).
What it names
A shape rather than a level — the swell itself — which is why it usefully describes any build toward a climax, in music or in an argument.
Example
Strictly, the crescendo is the swelling — so calling a peak "the crescendo" reverses the word’s original sense.
Related idea
A crescendo is a getting-louder; its opposite, a decrescendo or diminuendo, is a fading-away. Both name a change in volume, not a fixed dynamic like loud or soft.