A primitive root (identical with arab through the idea of covering with a texture); to grow dusky at sundown -- be darkened, (toward) evening.
see HEBREW arab
H6150. arab
[עָרַב] verb denominative become evening; grow dark (?); —
Qal. Infinitive construct לַעֲרוֺב הַיּוֺם רָפָה Judges 19:9, but read probably ᵐ5 לַעֶרֶב הַיּוֺם נָטָהL GFM; Perfect3feminine singular figurative עָֽרְבָה Isaiah 24:11 all joy has grown dark, but read עָֽבְרָה has passed away Lo Gr PerlesAnal. 91 CheHpt and others
Hiph`il Infinitive absolute וְהַעֲרֵב הַשְׁכֵּם 1 Samuel 17:16 doing it at morning and at evening.