An etymological comment about the Tocharian verb tätk-.
Résumé
The Tocharian verb tätk-, attested in both languages (A and B) means 'to extend', especially 'to prolong' (the life), as shown by D.Q. Adams (2014). It is proposed to connect this verb with the Proto-Indo-European root *tend- 'to extend, stretch' (cf. Lat. tendere). According to the pattern of Tocharian verbs in -tk-, as ascertained by H.C. Melchert (1977), it is based on the *-sḱe/o- present of a verbal root ending in dental, in the present case the zero grade *tṇd- of the root *tend-.