interval of the intercolumniation of the Doric column, which is observed by the intervention of one triglyph only between the triglyphs which come over the axes of the columns. This is the usual arrangement, but in the Propylaea at Athens there are two triglyphs over the central intercolumniation, in order to give increased width to the roadway, up...
• (n.) A kind of intercolumniation in an entablature, in which only one triglyph and two metopes are introduced.
Mon`o·tri'glyph noun [ Mono- + triglyph : confer French monotriglyphe .] (Architecture) A kind of intercolumniation in an entablature, in which only one triglyph and two metopes are introduced. 
In architecture a monotriglyph is a kind of intercolumniation in an entablature, in which only one triglyph and two metopes are introduced.
monotriglyph Having only one triglyph in the space over an intercolumniation.
(in the Doric order) any intercolumniation having one whole triglyph.