General Definition: 1. The act of bringing two similar shaped or interlocking objects together so that one fits inside the other, or any thing or any action directly or indirectly associated with this. As a Noun: 1. The condition of being the right size or shape to go onto or into another thing. English = fit. As a Verb or Adjective: 1. To fit two pieces of an interlocking device together. English = insert.