What is the collective noun for word plaque?

There isn't a specific collective noun for "plaque". You would need to describe the plaques in context to find a fitting term.

Here are some options depending on the situation:

If the plaques are commemorative:

* A collection of plaques

* A display of plaques

* A series of plaques

* A memorial of plaques

If the plaques are medical:

* A buildup of plaque

* A layer of plaque

* A deposit of plaque

If the plaques are decorative:

* A set of plaques

* A group of plaques

* A collection of plaques

Ultimately, the best collective noun will depend on the specific context and what you are trying to convey.