From BiblePortal Wikipedia

Vine's Expository Dictionary of OT Words [1]

Gebûl ( גְּבֻל , Strong'S #1366), “boundary; limit; territory; closed area.” This word has cognates in Phoenician and Arabic. It occurs about 240 times in biblical Hebrew and in all periods. Gebûl literally means “boundary” or “border.” This meaning appears in Num. 20:23, where it signifies the border or boundary of the entire land of Edom. Sometimes such an imaginary line was marked by a physical barrier: “… Arnon is the border of Moab, between Moab and the Amorites” (Num. 21:13). Sometimes gebûl denoted ethnic boundaries, such as the borders of the tribes of Israel: “And unto the Reubenites and unto the Gadites I gave from Gilead even unto the river Arnon half the valley, and the border even unto the river Jabbok, which is the border of the children of Ammon …” (Deut. 3:16). In Gen. 23:17, gebûl represents the “border” of an individual’s field or piece of ground: “And the field of Ephron, which was in Machpelah, which was before Mamre, the field, and the cave which was therein, and all the trees that were in the field, that were in all the borders round about, were made sure.” Fields were delineated by “boundary marks,” whose removal was forbidden by law (Deut. 19:14; cf. Deut. 27:17).

Gebûl can suggest the farthest extremity of a thing: “Thou hast set a bound that they may not pass over; that they turn not again to cover the earth” (Ps. 104:9).

This word sometimes represents the concrete object marking the border of a thing or area (cf. Ezek. 40:12). The “border” of Ezekiel’s altar is signified by gebûl (Ezek. 43:13) and Jerusalem’s “surrounding wall” is represented by this word (Isa. 54:12).

Gebûl represents the territory within certain boundaries: “And the border of the Canaanites was from Sidon, as thou comest to Gerar, unto Gaza; as thou goest, unto Sodom, and Gomorrah, and Admah, and Zeboim, even unto Lasha” (Gen. 10:19). In Exod. 34:24, Num. 21:22, 1 Chron. 21:12, and Ps. 105:31-32, gebûl is paralleled to the “territory” surrounding and belonging to a city.

Gebûlah the feminine form of gebûl occurs 9 times. Gebûl means “boundary” in such passages as Isa. 10:13, and “territory” or “area” in other passages, such as Num. 34:2.

Webster's Dictionary [2]

(n.) That which indicates or fixes a limit or extent, or marks a bound, as of a territory; a bounding or separating line; a real or imaginary limit.