Var. taḫḫūmu, tuḫūmu. Comparable lexemes are well known to occur in Rabbinic Hebrew, Aramaic and Arabic: Rabbinic Hbr. tǝḥūm 'dominion, area, district, border, limit', Off. Arm. tḥ(w)m 'border, boundary; territory', Nab. tḥwm 'id.', Plm. tḥwm 'id.', JPA tḥūm 'border, limit, area', CPA tḥwm 'border, limit, boundary; territory, region, district', JBA tḥūmā 'border, limit', Syr. tḥumā 'limit, boundary, border; precept, regulation, penalty; definition, term', Mnd. tauma 'boundary, frontier, limit', Arb. taḫm-, tuḫm- ‘limit, boundary’. The relationship between the Akkadian and WS words has been debated. Most scholars surmised an Akkadism in Aramaic, which seems reasonable. Kaufman 1974:105–106 rejects the borrowing hypothesis, however his arguments do not seem quite valid, see the discussion in EDA II. As for ḫ in Arabic, since the merger of *ḥ and *ḫ in Aramaic is a comparatively late phenomenon, it may not affect relatively early Aramaisms in Arabic (Kogan 2011:115–116, 2012:240).
One cannot rule out that both the Akkadian (in fact, Assyrian) and Aramaic lexemes were once independently borrowed from a third source. In this connection, the Indo-Iranian lexemes designating ‘seed, semen, progeny’ are noteworthy: Old Persian taumā- 'family' (> Neo-Persian tuxm), Avestan taoḫman- 'seed, offspring', Sanskrit tok#m ‘offspring, children’ (see KEWA I 527, Kent 1953:185, EDPL II 242–243). Phonetically, these terms come rather close to the Akkadian and Aramaic words, and the semantic shift from ‘progeny, family’ to ‘country, area’ is conceivable. The possibility of an early Indo-Iranian borrowing is thus not to be neglected.