可能来自pet,宠爱，宠儿，-ish,形容词后缀。引申词义得宠的，任性的，使性子的。
It has naturally been assoc. with PET sb.1, as being a characteristic habit of a "pet" or indulged and spoiled child; but the connexion of sense is not very clear or simple .... [OED]Related: Pettishly; pettishness.
来自辞典例句
