Lexitechnia

Caesar, invading Britain in 54 BC (De Bello Gallico 5.17):

Sed meridie, cum Caesar pabulandi causa tres legiones atque omnem equitatum cum C. Trebonio legato misisset, repente ex omnibus partibus ad pabulatores advolaverunt, sic uti ab signis legionibusque non absisterent.

But at noon, when Caesar had sent three legions and the whole cavalry to forage with the legate Gaius Trebonius, [the enemy] swooped down on the foragers suddenly from all directions; indeed, they did not hold back from the standards and the legions.

I’m not entirely sure I’ve understood the expression sic uti … non absisterent correctly. “So that” seems entirely the wrong relation for this sentence, and I’m not sure the replacement I have is much better; I’m sure not having a fully clear idea of the sense of absistere doesn’t help much either.

[For absisto.]