Definitions

Chadwick & Ventris 1973: table adjective, obscure
Bernabé 1998: 8-shaped, cf. ἀμφίβροτος covering the whole man, of a shield
Bernabé & Luján 2008: table adjective
cf. ἀμみゅーφふぁいιいおた around + -τος verbal adjective from of βαίνω go
  1. round
  2. with a rim

References

Chadwick, John and Michael Ventris, 1973 Documents in Mycenaean Greek

Bernabé, Alberto, 1998 Corolla Complutensis in memoriam J.S. Lasso de la Vega contexta (editors L. Gil, M. Pastor Martínez, R.M. Aguilar) "Hom. ἀμφιβροτος y mic. a-pi-qo-to, ¿un caso de etimología popular?"

Bernabé, Alberto and Eugenio Luján, 2008 A Companion to Linear B: Mycenaean Greek Texts and their World (editors Yves Duhoux and Anna Morpurgo Davies) "Mycenaean Technology"