WordWeb Online

1. The work of inquiring into something thoroughly and systematically
   - investigation

1. Study, try to understand; examine scientifically
   "Let's investigate the syntax of Chinese";
   - look into
    
2. Conduct an inquiry or investigation of
   "The district attorney's office investigated reports of possible irregularities";
   - inquire, enquire [Brit, Cdn]

Type of: analyse [Brit, Cdn], analyze [N. Amer], canvass, examine, probe, study, work

Encyclopedia: Investigating