ʿirq

عِرْق

a sea of sand dunes; a long ridge of sand; vein; root

قضى الباحثون أسبوعًا في العِرْق الشرقي الكبير يدرسون حركة الكثبان.
The researchers spent a week in the Grand Erg Oriental, studying how the dunes move.
نبض عِرْق في صدغه وهو يحاول أن يكتم غضبه.
A vein throbbed at his temple as he tried to hold back his anger.