From an unused root meaning to pile up; properly, accumulated; i.e. (by implication) a summit -- middle, midst.
H2872. tabbur
טַבּוּר noun [masculine] highest part, centre (according to ᵑ9 ᵐ5 navel, so Late Hebrew id., and טִיבּוּר, Aramaic טִיבּוּרְיָא טִיבּוּרָא,) — הארץ טַבּוּר מֵעִם יֹרְדִים עָם הִנֵּה Judges 9:37 behold people descending from the highest part of the land; הארץ עַלטַֿבּוּר ישְׁבֵי Ezekiel 38:12 those dwelling upon the navel of the earth, i.e. upon the mountainous country of Israel, central and prominent in the earth.