1. (

• investigation ,
• investigating

) the work of inquiring into something thoroughly and systematically ;

1. (

• investigate ,
• look_into

) investigate scientifically; "Let's investigate the syntax of Chinese" ;

2. (

• investigate ,
• inquire ,
• enquire ,

) conduct an inquiry or investigation of; "The district attorney's office investigated reports of possible irregularities"; "inquire into the disappearance of the rich old lady" ;