investigatev. t.[L. investigatus, p. p. of investigare to investigate; pref. in- in + vestigare to track, trace. See Vestige.] To follow up step by step by patient inquiry or observation; to trace or track mentally; to search into; to inquire and examine into with care and accuracy; to find out by careful inquisition; as, to investigate the causes of natural phenomena.()v. i. To pursue a course of investigation and study; to make investigation.()