Noah Webster's New International Dictionary of the English Language

1. (v. t.) To insert; to intrude; to come between, either for aid or for troubling.

2. (v. t.) To place between; as, to interpose a screen between the eye and the light.

3. (v. t.) To introduce or inject between the parts of a conversation or argument.

4. (v. i.) To be or come between.

5. (v. i.) To step in between parties at variance; to mediate; as, the prince interposed and made peace.

6. (v. i.) To utter a sentiment by way of interruption.

7. (n.) Interposition.