"No word for adultery"

In the current (May 16) New Yorker, a review of Sarah Vowell's "Unfamiliar Fishes" describes early missionaries to Hawaii as

... wan New Englanders confronted with a people whose language lacked a word for adultery. (Their approximation: "Mischievous mating.") 

The "no word for adultery" is Vowell's conceit, apparently, and I haven't tried to check its accuracy. But what immediately struck me is that "mischievous mating" is about a million times more descriptive than "adultery." How did a word like that come to mean "illicit sex with a married person?"

(Now I'll go look it up.)