Esek

Quarrel, a well which Isaac’s herdsmen dug in the valley of Gerar, and so called because the herdsmen of Gerar quarrelled with them for its possession (Gen. 26:20).

(contention), a well which the herdsmen of Isaac dug in the valley of Gerar. (Genesis 26:20)

e'-sek (eseq; Septuagint Adikia):

The name given by Isaac to a well dug by his servants, for the use of which the herdsmen of Gerar strove with them-- "contention" (Ge 26:20). It lay in the neighborhood of Rehoboth and Gerar: but the site is not identified.