interpose

To insert or introduce between parts.

To place (oneself) between others or things.

To introduce or interject (a comment, for example) during discourse or a conversation. synonym: introduce.

To exert (influence or authority) in order to interfere or intervene.

To come between things; assume an intervening position.

To come between the parties in a dispute; intervene.

To insert a remark, question, or argument.

Interposal; interposition.

In chess, to put (a piece) between the checked king and the checking piece.