"Hjatir" means "custom" as in "tradition." For example, "The Amulet of Mara is a Nordic custom."

As for a word meaning "custom/personal," that's a tough one.  Something perhaps from "Meyar," "self." Once we have a word for that though, a word for "customize/personalize" will easily follow. That'll probably use the prefix "Ge-" to mean "to make custom or personal."

Custom is "Hjatir."
Source: http://www.thuum.org/translate.php