Entry 2 senses · 2 variants Webster, 1913 Investigable · In·ves·ti·ga·ble · IPA a. a. 01 a. Capable or susceptible of being investigated; admitting research. 1. Capable or susceptible of being investigated; admitting research. 02 a. Unsearchable; inscrutable. 1. Unsearchable; inscrutable.[Obs.] “So unsearchable the judgment and so investigable the ways thereof.” — Bale.