The Hebrew proper name Nachuwm (Nahum) means "comforter" or "full of comfort." From the root nacham (H5162, to comfort), this name belongs to the prophet who authored the book of Nahum, prophesying the destruction of Nineveh, the capital of the Assyrian empire. He is identified as an Elkoshite.
The prophet Nahum delivered a message of divine vengeance against Nineveh — the very city that had repented under Jonah's preaching but later returned to extreme wickedness. His name "Comforter" is significant: while his prophecy is fierce judgment against Assyria, it is simultaneously a message of profound comfort to Judah, assuring them that their brutal oppressor would be destroyed. God's justice against the wicked is comfort to the righteous.