Spanish enano ‘dwarf’ developed from the synonymous Latin nanus, which the Romans had taken from the Greek nanos or nannos that meant ‘little old man’ and ‘dwarf.’ Where Latin extended nanus semantically to include ‘a small horse’ and ‘a type of low, shallow water-vessel,’ Spanish extended the word phonetically, seemingly by adding what linguists call an epenthetic or “support” vowel at the beginning; the default epenthetic vowel in Spanish is e, as we see in words like Esteban/Steven, espada/spade, and escándalo/scandal. But as those examples show, Spanish usually feels the need for support only in words that originally began with s- followed by a consonant. Joan Corominas suggests that the e- of enano could have come from a crossing of the earlier form nano with the Old Spanish enatío that meant ‘ugly’ or ‘deformed.’
As for the older Spanish nano, speakers of English (as well as those of Spanish) recognize its modern use as a metric prefix meaning ‘one-billionth.’ Scientists know a nanometro/nanometer as ‘one one-billionth of a meter,’ but etymologically it’s ‘a dwarf of a meter’ (oh, the imagination of those who ply the sciences). English nanosecond is a scientific term that has gained currency in the language due to its occurrence in measurements of the time it takes a computer to read from or write to random-access memory (RAM). Because of that association, nanosecond has taken on a life of its own with the generalized meaning ‘a very short period of time, an instant.’ Writer James A. Haught took advantage of the dual senses when he titled his 1991 book Science in a Nanosecond. And in 2005, when Apple released a smaller version of its popular iPod, it called the new model the iPod Nano, which it hoped people would run out and buy in a nanosecond.
© 2011 Steven Schwartzman