Word

Hello

I am looking for a particular word, but am unable to find it.

Just as the 'snazzy' word for "a common spoken phrase" is a colloquialism, I wish to know the 'snazzy' word for a word that is the name of a country/city/organisation and has been chosen to act as a reminder for something.

Example: A group of people make an agreement to leave society and live amongst themselves as a community; they call themselves the Covenant. They have chosen this word because it means "agreement" and it is intended to remind them of the agreement they made.

I wish to know the 'snazzy' word that describes "Covenants" purpose, apart from being the name of something.

I'm not sure if I am making any sense? Lol.

Thanks
Sebastien