to place between; cause to intervene

to interpose an opaque body between a light and the eye.

to put (a barrier, obstacle, etc.) between or in the way of.

to put in (a remark, question, etc.) in the midst of a conversation, discourse, or the like.

to bring (influence, action, etc.) to bear between parties, or on behalf of a party or person.

to come between other things; assume an intervening position or relation.

to step in between parties at variance; mediate.

to put in or make a remark by way of interruption.

verb

inject , insert , interject , interlard , interpolate , arbitrate , intercede , interfere , interrupt , intervene , introduce , mediate , moderate , negotiate , sandwich

noun

arbitration , interpolation , interposition , mediation