Verb for the inverse of greet

Is there a verb for the inverse of greet, or a synonym verb for greet that has an inverse verb? Everything I can think of is a verb phrase, exclamation, or noun. Salute is the closest I could find, but it's applicable to arriving and departing.

For context, I’m writing a hello world example of a class and would like to add a method for the inverse of greet to the class to show classes are collections of attributes and behaviors. As a behavior, the method name should be a verb or start with one.

The single-word verbal opposite of greet (as in a host welcoming guests) is dismiss:

1 : to permit or cause to leave
// dismiss the visitors
// Class is dismissed.

In your case, the function name could be dismiss().

To add to this, Hello, world! would be what was said at greeting, and, for example, Goodbye, world! would be what was said at dismissal.

The thing that you are saying when you are seeing people off is a valedictory, and the action itself is called a valediction:

valedictory n. an address or statement of farewell or leave-taking

valediction n. an act of bidding farewell
_{definitions from m-w.com}

One would think, therefore, that the verb form is valedict. This, unfortunately, is not listed in any dictionary that I can find. However, it being for a programming exercise, you are free to use anything that you want. (Indeed, that's why "help with naming things in programs" is explicitly off-topic.) And valedict is clearly and obviously appropriate (if you are familiar with your Latin roots, at least: vale = 'goodbye', dict = 'speak').

In your context "To greet" is to say "Hello" to someone entering your presence (your locality). The opposite would be to wish someone farewell as they leave. This would be saying "Goodbye" or "Farewell".