FROM STRONG’S HEBREW DICTIONARY (1890)

Strong’s Hebrew Dictionary (1890) — public domain, printed whole.

qadar kaw-dar' — a primitive root; to be ashy, i.e. dark-colored; by implication, to mourn (in sackcloth or sordid garments):--be black(-ish), be (make) dark(-en), X heavily, (cause to) mourn.