Grammarians who pen English usage guides do not seem piqued at the misuse of the words peek, peak, and pique. Theodore M. Bernstein notes only that piqued “takes [the] preposition at or by.” Even college-level writers’ guides make little fuss. Flipping to the usage sections of several writers’ guides, one finds a no-show for the peeks. Webster’s Dictionary of English Usage, however, writes that “[t]hese homophones have a way of being muddled by nodding writers.” Relying on former newspaper columnist and grammarian James J. Kilpatrick, who had caught misuses among the peaks in various news publications, the entry notes that peak most frequently edged out its competitors and inappropriately made its way into print. The entry ends by warning writers “to keep the meaning in mind and match it to the correct spelling.”
English usage of peek is traced to 1374 and stems from the Middle English piken, which some sources speculate comes from the Middle Dutch kieken. Peek means “to glance at quickly, or to peer at furtively, as from a place of concealment.” As a verb, it means that something is “only partially visible…[t]iny crocuses peeked through the snow.” The expression peek-a-boo is “attested from 1599,” according to the Random House Dictionary.
Peak is traced to 1520-1530, perhaps from the Middle Low German words pick and pike, according to Random House. As a noun it has several meanings, some of which point to the top of a mountain, ridge, or summit. It can also be used to describe a “projecting part of a garment,” as in the bill of a hat. Nautically, it means the “upper most corner of a fore-and-aft sail” or the “narrow part of a ship’s bow.” As an intransitive verb, it means reaching “maximum capacity, value, or activity,” as in “My running pace peaked at 10 minutes per mile.” Similarly, as an adjective, reaching peak levels demonstrates that one has maxed out.
In a less common usage, those who grow sick or thin are sometimes spoken of as having peaked or “dwindled away” or, as an adjective, being peaked (2 syllables), “being pale and wan or emaciated: sickly.”
Emotion rules pique. It stems from the Vulgar Latin verb piccare, “to pick,” and its usage in English is traced to 1525-1535. It is menacingly linked with pickax and pike. As a noun, it is defined as “a transient feeling of wounded vanity.” Or, as one might say of a woman scorned, “She’s in a fit of pique.” But a woman moves quickly on, pique being a transient emotion. As a verb it means that someone has been “aroused” to “anger or resentment.” Or, as I like to use it, aroused to the state of curiosity.
Although they sound alike and to an extent they look alike, the piques are as different as … Has your interest peaked? (Begs for a pun, doesn’t it?)—Beverly Stewart, MSJ