The story
Iktsuarpok is Inuktitut, the language of the Inuit of the Canadian Arctic, and in its own syllabic script it is written ᐃᒃᑦᓱᐊᕐᐳᒃ. The meaning known in English comes from Arthur Thibert's Eskimo–English dictionary, which glosses it as 'goes outside often to check if someone is coming'. That gloss is a whole sentence, and that is no accident: Inuktitut builds words from a root and a chain of endings, so one word can carry what English needs a clause for.
In English the word has been taken up as a noun for the feeling behind the habit: the restless anticipation of waiting for someone, which keeps sending you to the window. It turns up on many lists of words other languages lack, often without the detail that the original describes what someone does rather than what they feel.
What makes it hard to translate is that English has the feeling, impatience, and the action, checking, but no single word that holds both. Iktsuarpok is the feeling seen from outside: you know it is there because someone keeps going to look.
A scene: Christmas Eve in a terraced house, a daughter driving up from Bristol. Her mother has laid the table twice. Every few minutes she lifts the corner of the curtain at the sound of a car, and once she goes out to the gate in her slippers. The modern version is quieter: refreshing the delivery tracker on your phone, though nothing has changed for minutes.