וְיָקְטָ֣ן יָלַ֔ד אֶת־אַלְמוֹדָ֖ד וְאֶת־שָׁ֑לֶף וְאֶת־חֲצַרְמָ֖וֶת וְאֶת־יָֽרַח׃
At si Joktan ang naging ama ni Almodad, at ni Sheleph, at ni Hazarmavet, at ni Jerah,
Rashi
חצרמות He was so called (Court of Death) after his city. So is the statement of the Agada (Genesis Rabbah 37:8).
Radak
חצרמות, this is one word though it may sound as if it should be two words.
Siftei Chakhamim
He was so called because of his city. [The Aggadah explains that] the people of that city awaited death [מות] every day, because they [were very poor] and ate animal fodder.