Thanking as an action

I want to create a new verb, ‘thanking,’ but I’m having problems.
Obviously, I want the player to “thank” an NPC.

Thanking [someone] is an action.

Result:

Problem. You wrote ‘Thanking is an action’ : but it is not sufficient to say that something is an ‘action’, without giving the necessary details: for example, ‘Unclamping is an action applying to one thing.’

Thanking is an action applying to one visible thing.

Can that one visible thing be an NPC?

Yes, it can be anything the player can see.

Thanks!