From aqab; in the original sense, a knoll (as swelling up); in the denominative sense (transitive) fraudulent or (intransitive) tracked -- crooked, deceitful, polluted.
see HEBREW aqab
H6121. aqob
I. עָקֹב adjective
1 insidious, deceitful, Jeremiah 17:9 מִכֹּל הַלֵּב עָקֹב.
2 foot-tracked (denominative from I. עָקֵב) Hosea 6:8 מִדָּם עֲֹקֻבָּה אָוֶן מֹּעֲלֵי קִרְיַת גִּלְעָד.
II. עָקֹב adjective steep, hilly (see √; compare difficult mountain path, Qor 90:11 hill); — Isaiah 40:4 לְמִישׁוֺר הֶעָקֹב והיה let the steep ground (Chronicles) become a plain ("" הָֽרְכָסִים). compare Ecclus 6:20.