A gharīb word is one whose meaning is unfamiliar to a particular reader or group, even though it has an established usage among speakers of the language. Its interpretation requires attention to attested usage, root, possible senses, and context.
Unfamiliarity does not make the expression non-Arabic or meaningless. A genuinely Arabic word may simply have become rare in ordinary speech.
Where a word has several possible meanings, it is not sound to assign all of them indiscriminately to one verse. Contextual evidence must guide selection.