Definitions for "Interjection"
A word or form of speech thrown in to express emotion or feeling, as O! Alas! Ha ha! Begone! etc. Compare Exclamation.
PS a traditional part of speech ( ¶2-6-10) being words usually contained in introverted utterances, used to vent emotion, such as, Uch! ¶6-1-4. Single word variations of socially motivated expressions also belong to the class of i., such as, Hurrah! ¶6-1-5. The exclamatory words of this class are sometimes called expletives.
A word (one of the eight parts of speech) expressing a simple exclamation: Hey! Oops! When used in sentences, mild interjections are set off by commas: Oh, excuse me.
Keywords:  throwing, act
The act of interjecting or throwing between; also, that which is interjected.