In formal contracts, it’s normal to include the definitions of key words referenced in the contract. A longer agreement may even include an annexed glossary. Discerning parties sometimes argue about the definitions before reaching consensus and signing.
In discussions aimed at bringing about organisational changes, the definitions of abstract terms employed in the discussions should be agreed upon as well. Agreeing on definitions reduces argument time later down the line. It also assists the parties in sharpening their thinking, so that they are better able to developing clear, measurable goals.
Defining terms doesn’t always have to be done before starting such a discussion. After all, we may not know what terms are going to come up. Definitions can be done on the fly too, by looking up each term as it pops up during the initial conversation, and agreeing on a definition that fits the intended meaning (or by switching to a different term which more accurately describes what was meant, and recording that definition instead). The definitions can then be collated and distributed in preparation for the next round of discussions, and updated as the discussions continue. Eventually, the glossary developed by this process becomes an organisational asset.