The strange (because of its semantics) Spanish verb chapuzar means, in the definition of the DRAE, ‘Meter a alguien de cabeza en el agua,’ which is to say ‘To put someone head-down into the water.’ Definitely not helpful to breathing, right? Why a language needs a verb like that isn’t obvious, nor, due to phonetic changes, is it obvious where the verb came from. The modern form of the word goes back to the end of the 1500s, but in the 1200s the verb was zapuzar and before that sopozar, in which we can finally begin to recognize the elements of the compound. The so- developed from Latin sub ‘under,’ and the second element is the same as in pozo ‘a well,’ so the notion was ‘[to put someone] under [the water in] a well.’
And what about the ‘head first’ part of the modern meaning? Joan Corominas gives the answer to that when he explains the change in the second vowel that took place on the way from sopozar to zapuzar. It seems there was influence from the similar-sounding and -meaning verb capuzar that had arisen from Latin caput ‘head.’ In essence, the two verbs merged—dare we say got submerged?—and chapuzar was the eventual result.
Although probably no connection to English comes to mind (other than the many words with sub- as a prefix), there is one. Spanish pozo developed from Latin puteus ‘a water well,’ which ultimately surfaced in the Old English borrowing pytt, the source of the modern noun pit whose fundamental meaning is ‘a cavity in the ground.’ That’s a different word from the pit that’s ‘the kernel in a fruit,’ but the same pit that as a verb means ‘to set in opposition,’ as when one candidate for political office is pitted against another. The semantic connection is via the type of pit that people have traditionally made in the ground for the purpose of staging combats, as for instance roosters in a cockpit. By another transference, the fact that a cockpit is a small, enclosed space led to the now-primary sense of the word: ‘the compartment in which the pilot of an airplane sits.’
© 2015 Steven Schwartzman