Lewis & Short

Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.

rătĭōcĭnor, ātus, 1, v. dep. n. and a. [ratio] (rare, but good prose).

  1. I. Lit., to reckon, compute, calculate: in summo apud illos (sc. Graecos) honore geometria fuit: itaque nihil mathematicis illustrius; at nos metiendi ratiocinandique utilitate hujus artis terminavimus modum, Cic. Tusc. 1, 2, 5: de pecuniā ratiocinari, id. Inv. 2, 39, 115; 2, 32, 125; Vitr. 10, 15.
  2. II. Transf.
    1. A. To consider, deliberate, meditate: quo pacto cum illis occipiam, id ratiocinor, Plaut. Stich. 1, 2, 18: socii profecto ratiocinati essent quid possent facere, si quidem suā sponte facerent, Auct. Her. 4, 11, 16.
    2. B. To reason, argue, to infer or conclude from a consideration of circumstances: id ex partibus juris sumi oportebit et ratiocinari, quid in similibus rebus fieri soleat, et videre, utrum, etc., Cic. Inv. 2, 20, 61; cf. Auct. Her. 2, 23, 35; Quint. 7, 1, 61: etenim sic ratiocinabantur … aperte jam ac perspicue nulla esse judicia, etc., Cic. Verr. 1, 7, 20; cf. id. Mil. 12, 32; id. Phil. 2, 22, 55.
      Rarely with acc.: mores atque parsimoniam alicujus, App. M. 1, p. 113, 5.