Words and Proper Names

acus

4181.
Hamp (Eric P.): Varia: III. 3. acusocuis.
In Ériu 32 (1981), pp. 159–161.
Argues it derives from a PIE idiom *adĝ(h)osti- ‘that which is at/to hand’, which has a semantic parallel in Lat. praestō < *prae-hest-ōd (cf. PIE *ĝ(h)es- ‘hand’).