taḥat - below, underneath; what is located undemeath
(HALOT 1721)
Hebrew
təkēlät - a blueish or violet coloured purple wool
(HALOT 1733)
Cannot be separated from Akk. takiltu ‘a blue-purple wooľ (an exact vocalic match to the Hebrew word), JPA toklā ‘purple wooľ, CPA twklɁ‘blue fabric’, JBA tǝkēltā ‘tekhelet color’, Syr. tekltā ‘color caeruleus, purpureus’. Their futher etymology is unknown.
Hebrew verb and Pho. tmk 'to take, to seize' are hard to separate from Akk. tamāḫu 'to seize, to grasp; to controľ, very similar both phonologically and semantically. The irregular correspondence -k vs. -ḫ is deemed to remain without explanation