detrimentosus
From LSJ
τους φίλους λόγων τέχναιν επαίδευσας → Using 2 artifices, you educated (taught) those who love rhetoric.
Latin > English (Lewis & Short)
dētrīmentōsus: a, um, adj. detrimentum,
I hurtful, detrimental: ab hoste discedere detrimentosum esse existimabat, Caes. B. G. 7, 33.
Latin > French (Gaffiot 2016)
dētrīmentōsus,¹⁶ a, um (detrimentum),désavantageux, préjudiciable : Cæs. G. 7, 33.