o·ver·heat / ˌōvərˈhēt/ • v. make or become too hot: [intr.] her car started to overheat | [tr.] it's vital not to overheat the liquid. ∎ make too excited: [as adj.] (overheated) his overheated imagination. ∎ Econ. (of a country's economy) show marked inflation when increased demand results in rising prices rather than increased output: [intr.] lending rates could soar as the economy overheats | [tr.] credit expansion helped overheat the economy.