Exegesis:

exelthonta de ta daimonia apo tou anthrōpou eisēlthon eis tous choirous ‘and after coming out of the man the demons went into the pigs.’ For exelthonta … apo tou anthrōpou cf. on 4.35.

kai hōrmēsen hē agelē ‘and the herd rushed.’

hormaō ‘to rush (headlong).’

kata tou krēmnou ‘down the steep slope.’ The article tou has the same function as that in en tō orei in v. 32.

krēmnos (only here and parallels in the N.T.) ‘(steep) slope,’ ‘bank,’ ‘cliff.’

apepnigē ‘and was drowned,’ from apopnigō ‘to choke,’ cf. on v. 7.

Translation:

Were drowned. Corresponding terms may require a reference to death, e.g. ‘died sinking/choking’ (Balinese, Bahasa Indonesia), or simply, ‘died’ (Sranan Tongo).

Quoted with permission from Reiling, J. and Swellengrebel, J.L. A Handbook on the Gospel of Luke. (UBS Handbook Series). New York: UBS, 1971. For this and other handbooks for translators see here . Make sure to also consult the Handbook on the Gospel of Mark for parallel or similar verses.