How do I say... Goodbye

Klingons wouldn't usually say anything when leaving. However, like with the Hello, there are number of phrases that might be used instead.

The expressions on this page, with the exception of pItlh, should be considered as literal statements, and should only be said when they are true, not out of politeness.

pItlh

pItlh means "Done" as in "I'm done" or "It's done". Many people use it at the end of their emails. It can be used sometimes when leaving to mean "I'm done (and therefore I'm not needed here anymore)" (Maltz used it one time when leaving the room after discussing with Okrand(1)).

Some people use pItlh to mean "I've said all" or "I'm done speaking" and say it at the end of their speech. During video calls it is common to say pItlh just before leaving, in same style as e.g. Captain Picard would say "Picard out" at the end of a video call.

rIn

The verb rIn literally means "be accomplished, finished". In Star Trek VI: The Undiscovered Country, it was used as the final word in a radio transmission and translated as "over". Some people use that as a closing word in their email.

DaH jImej

DaH jImej is used in Talk Now to mean "Goodbye", but it actually just means "I will now leave". Some people say DaH jImejnIS.

maghomqa', maghomqa'jaj

maghomqa' means "We will meet again". The variation maghomqa'jaj ("May we meet again") is also used.

Qapla'

This word appears at the end of the list intentionally, because it is not really a good way to use for "goodbye". The word Qapla' means "success" and it should only be used in that meaning. It is okay to wish somebody success as a farewell phrase, but it should not be overused.

References

1 : http://klingonska.org/canon/search/?file=2003-06-holqed-12-2.txt&q=pItlh