Lewis & Short

in-cōgĭtābĭlis, e, adj.

  1. I. Act., thoughtless, inconsiderate (ante- and post-class.): nunc demum scio, me fuisse excordem, caecum, incogitabilem, Plaut. Mil. 2, 6, 63; Lact. 1, 8.
  2. II. Pass., inconceivable, incomprehensible (post-class.): immensitas efficientiae, Mart. Cap. 9, § 922: dementia, Amm. 15, 3: incogitabile est, eandem esse causam, etc., Fragm. Jur. Civ. p. 23 Mai.