* A misspelling:
* "Impinge" means to have an effect or impact on something.
* "Impound" means to seize and hold something, usually by legal authority.
* "Impinging" is the present participle of "impinge."
* A regional dialect word: Some words have very specific regional uses. It's possible "impong" exists in a particular place or dialect.
* A made-up word: Sometimes people create new words for specific purposes.
To understand the meaning, please provide more context. For example:
* Where did you encounter this word? (book, conversation, online)
* What was the sentence it was used in?
* What do you think the word might mean?
This information will help me figure out what "impong" actually refers to.