I think I am getting confused here now, Piotr, so I will
restate myself.
Pokorny, IEW, page 1079 -
*TEU- (2)
"in freudlichem Sinne die Aufmerksamkeit zuwenden.
aufmerken"
Old Irish Tuas-cert "noerdlich (northernly)" >
*TEU-STO
Breton Tus "links (left)" > *Teu-sto
Welsh Tut "Zauberer(magician)" < *TEU-TO
Old Irish Tuath "left, noerdlich, boese (left, northernly,
evil)" < *TEU-TO
Old Irish Tuaith "noerdlich"
Incidentally, Pokorny IEW pg. 1080,
*TEU- (with long -E-, as opposed to the *Teu above with short
-e-)
"schwellen" (swell)
This is the root for *Teu-t-a from which Irish Tuath "tribe"
and and German Diota derives