Gai

GAI gā’ ī (גַּ֔יְא, LXX Γεθ, Γαι, valley, RSV Gath, KJV the valley). A locality mentioned in 1 Samuel 17:52 together with Ekron as the limit to which the Israelites chased the Philistines after the victory of David over Goliath. The absence of the article in MT argues against tr. “the valley” as in KJV. The last half of the verse, as well as the reading of the LXX and the Syriac, strongly suggests the reading “Gath” as in RSV.

International Standard Bible Encyclopedia (1915)

(gay’):

In the Revised Version (British and American) of 1Sa 17:52 for the King James Version "valleys." the Revised Version, margin notes: "The Syriac and some editions of the Septuagint have Gath" (thus also Wellhausen, Budde, Driver, etc.).