"Econ" is a shortened form of "economics." It refers to the study of how people and society make choices on how to use limited resources to satisfy their needs and wants. Full definition
When not in Econ mode it is a civic that can be changed to sport mode where the electric motor actually will kick in a few extra horsepower like the old accord hybrid did. (hybridcars.com)
Where other 2012 Civics feature a big green Econ button to the left of the steering wheel, the Si has only a button to disable the traction control. (cnet.com)
You can't go by the EPA mileage rates because that doesn't take into consideration the option to drive in Econ mode to increase fuel efficiency. (edmunds.com)