Scientists believe that one of the causes of the obesity epidemic sweeping the U.S. is our sedentary lifestyle. Sedentary means sitting a lot and refers to a person or job that is not very physically active.
If you have a sedentary job, you might want to stand up and stretch every hour or so, and if your doctor says that you are too sedentary, she means that it would be healthier for you to exercise more. This adjective has a specialized meaning when referring to certain types of birds that stay in one area and do not migrate. Sedentary comes into English from French sédentaire, which is derived from the Latin word sedēre, "to sit."