Words related to mono-
The secondary sense of monotonous (same or tedious) has so nearly swallowed up its primary (of one pitch or tone) that it is well worth while to remember the existence of monotonic, which has the primary sense only. [Fowler, 1926]
"animal of the lowest order of mammals," native to Australia and New Zealand, which have one opening for the genital, urinary, and digestive organs, 1833, from Monotremata, the order name, Modern Latin, neuter plural of monotrematus, from Greek monos "single, alone" (see mono-) + stem of trēma "perforation, hole, opening; eye of a needle, dot on dice," related to tetrainein "to bore through, perforate" (from PIE root *tere- (1) "to rub, turn"). Related: Monotrematous.
1881 in biology, "the single or sole type of a species in its genus, a genus in its family, etc.;" 1882 in printers' arts, "a print from a picture painted on a metal plate" (only one proof can be made, as the picture is transferred to the paper); 1893 as a brand name of typesetting machine; see mono- + type. Related: Monotypic (1878 in the biological sense)