double window

One having two sets of sashes, inclosing a body of air as a non-conductor of heat and to deaden noise. double X or XX, 8. A name given to porter or beer of more than ordinary strength. According to Palmer, a survival, in a somewhat disguised form, of the Lat. word duplex (misunderstood as double X), which formerly was commonly applied to such. doub'-led (led as eld), pa.par.ora. [DOUBLE, v.] doŭb-le-ne , *doub-le-ne e (le as el), s. [Eng. double; -ne .] I. Literally : 1. The state of being double, duplicate, or two fold. 2. The state of being twice as great or twice as much. *II. Fig .: Double-dealing, deceit, duplicity, treachery.