Lewis & Short

ductim, adv. [duco], by drawing (very rare): major pars operis in vinea ductim, potius quam caesim faciendaest (for which, shortly after: ductu falcis, non ictu), Col. 4, 25, 2: invergere in me liquores, in good draughts, Plaut. Curc. 1, 2, 13 (cf.: pocula duces Lesbii, Hor. C. 1, 17, 21).