interjection
Interjection (noun) means a short word or sound, such as one showing surprise, that stands apart from the grammar of the sentence around it.
Etymology
From Middle English interjeccioun, from Old French interjection (13th century), from Latin interiectiōnem, accusative singular of interiectiō (“throwing or placing between; interjection”), perfect passive participle of intericiō (“throw or place between”), from inter (“between”) + iaciō (“throw”). Displaced Old English betwēoxāworpennes (literally “between-thrown-out-ness”), a calque of the Latin.