Livy 9.27.14 (tr. Betty Radice with her note):
In a short time the Romans began to win all along the line, while
the Samnites gave up the fight and were cut down or taken prisoner,
except for those who fled to Maleventum, the city now called
Beneventum.41 According to tradition some thirty thousand Samnites
were killed or captured.
41. Malventum or Maleventum had its name changed, as it sounded ill-omened, when a Roman
colony was settled there in 268; but the name was not derived from Latin male but from Greek
mēlon or malon, meaning 'sheep' (or possibly 'apple').
tota deinde
iam vincere acie Romanus et omisso certamine caedi capique Samnites, nisi qui
Maleventum, cui nunc urbi Beneventum nomen est, perfugerunt. ad triginta milia
caesa aut capta Samnitium proditum memoriae est.
Robert Maltby,
A Lexicon of Ancient Latin Etymologies (Leeds: Francis Cairns, 1991), p. 78:
Beneventum, -i n. (oppid. in Samnio). FEST. 340 Segestae praeposita est ... 's' littera, ne obsceno nomine appellaretur, ut factum est in Malvento, quod Beneventum dictum est (cf. LIV. 9,27,14. PLIN. nat. 3,105). PAUL. FEST. 34 Beneventum, colonia cum deduceretur, appellari coeptum est melioris ominis causa. namque eam urbem antea Graeci incolentes Μαλόεντον appellarunt. thes. gloss.