The English language has more than one word for 12 (twelve, dozen) and 12^2 (one hundred and forty-four, gross), but has there ever been a word for 2*12 other than twenty-four?
I would also be interested in whether other languages developed special words for the number twenty-four.
I am not aware of any current or archaic English word for 24 other than the obvious combinations like "double dozen" or "score and four" ("score" is 20). German style wording like "four-and-twenty" was occasionally used until 19th century, and survives in some idioms, see English SE.
One of the two formations (2x12 or 20+4) is typical in most languages. "Dozen" derives from Latin duodecim (2+10). Analogously, base 24 system is now called tetravigesimal (biunqual or binilimal are rarely used) from Latin tetra (4) and vigesimus (20). But no old French or English vulgarization emerged.
Some interpret Umbu-Ungu, the counting system of the Kaugel in Papua New Guinea, as base 24, although ethnologists call it 4-cycle system, see Owens et al., History of Number: Evidence from Papua New Guinea and Oceania, p.117ff. The word for 24 in it is tokapu, and it is not 2x12, which would be rurepo talu, or 20+4 (20 is supu and 4 is kise). It is used as a root to form larger numerals.
Of course, day in English is 24 hours, if one chooses to see it that way. Nychthemeron (from Greek núx, night, and hēméra, day) is occasionally used for periods of 24 hours to remove the ambiguity, and there are similar disambiguating words in other Western languages.
