• interdigital •
Pronunciation: in-têr-di-ji-têl • Hear it!
Part of Speech: Adjective
Meaning: No, the literal meaning of today's Good Word originally had nothing to do with electronic; it meant 1. "between digits, fingers or toes". Since the 1960s, however, a new metaphorical sense of this word has emerged: 2. "Having two interlocking comb-shaped arrays of metallic electrodes".
Notes: This word is related to the verb interdigitate, which means to "interlock like fingers" (see illustration). This verb gave rise to the second sense of the adjective interdigital. The adverb would be interdigitally. Otherwise, it has no family.
In Play: Whatever occurs between our fingers or toes is interdigital: "Athlete's foot, the most widespread interdigital disease, is difficult to cure." That includes anything growing there: "Otters have interdigital webs on their feet that help their submarine navigation."
Word History: Today's Good Word, yet again, is a borrowing from Latin (via French) interdigitalis. This adjective resulted from connecting inter "between" + digitus "finger or toe" + an adjective suffix. Inter was an extended form of PIE in "inside" that also went into the making of Greek enteron "intestine". Latin also made intro "inside, within" from the same extended form which we see in introduction. Digital once meant "referring to numbers less than 10". Latin digitus started out as PIE deik- "to show" that shows up in Greek deiknynai "to show", Latin dicere "to speak, say, tell", German zeigen "to show", and English teach. Since our ancestors used fingers mostly for pointing, we can see how it ended up as digitus in Latin (Thanks to William Hupy for today's Good Word, which should have come out of the computer world, but didn't.)