Literally: five – ri – fog/mist – middle
Alternately: Completely lost. Unable to grasp the current situation, and therefore unable to foresee what may come or lay out any sort of meaningful plan.
Notes: The ri (sometimes called a “Japanese league” or “Chinese mile,” depending on which culture you’re interacting with) is a unit of distance ranging from about 600 m to about 4 km. The character can also refer to a village or small town, specifically one’s hometown (in contrast to “the city”), or to an administrative division of 50 homes, or to an equivalent area. There’s a lot of history bundled up in there, and I suggest looking into it, but for our purposes here it essentially means that the fog is extensive.
Some people mistakenly render the latter half of this compound as 夢中 (also pronounced muchuu). The term means “engrossed,” or “in a daze / trance,” so it may seem appropriate, but this is an error that loses the reference to the five-ri fog.