The primary headword, presumably extracted from the first quotation given, is perfect middle/passive participle, feminine accusative singular, of sa/ttw. The secondary one, illustrated by the second and third quotations (but see below), is the corresponding masculine nominative plural.
[1] An approximation of Agathias, Histories 2.6 (p. 48 lines 8-12); the Romans seize a wagon from the foraging Franks, set it ablaze, and destroy a riverside watchtower, precipitating the Battle of the Volturnus (Battle of Capua, 554 CE) during the Gothic War (535-554); cf. Frendo (38). For additional context, also see delta 506, epsilon 953, lambda 387, mu 764, pi 87, and phi 700.
[2] Quotation unparalleled in this precise form but again, seemingly, a loose version of one or more passages in Agathias. For 'weighed down by their plunder', see next note; the rest echoes Agathias 3.7 (p. 92 line 30); but neither includes sesgame/noi.
[3] Agathias, Histories 2.10 (p. 54 line 15), on the triumphant return home of a Roman army; the finite verb, however, is added by the lexicographer.