To interject means to suddenly insert yourself into a conversation, often interrupting what someone else is saying. When you interject, you jump in with a comment or question before the other person has finished their thought.

Imagine your parents are discussing where to go for vacation, and you suddenly interject with, “Can we go somewhere with a beach?” You've inserted your opinion right into the middle of their conversation. Or perhaps your teacher is explaining a math problem when a student interjects to point out a mistake on the board.

Sometimes interjecting is rude, like when you interrupt someone telling an important story. Other times it's necessary and helpful, like when you interject to warn someone about danger or correct a serious misunderstanding.

In polite conversation, people usually wait for natural pauses before speaking. But when you interject, you're breaking in before that pause arrives. Teachers might say, “I don't mean to interject, but...” when they need to add something important to a student discussion. The phrase acknowledges that you're interrupting, but suggests you have a good reason for doing so.