PROTO: *śuśt(V)r(V)
MEANING: 1 root 2 stubble (of crops) 3 sting, prick (of snake) 4 foundation, origin
BZK: sustrai, zustrai 1, sustar, suster 1, 2, 3
GIP: sustrai 1, 4
ANV: sustrai 1
COMMENTS: A western Bsq isogloss. Cf. sirats 'nerve, vein, tendon' (Trask 1995; not in Azkue with this meaning). The BZK form zustrai is anomalous (not having the usual assimilation of sibilants) - influenced by *sul 'wood, tree'?
