Word Origin & History
1560s, the sound of the word perhaps somehow suggestive of low feelings (cf. Low Ger. mopen "to sulk," Du. moppen "to grumble, to grouse," Dan. maabe "to mope"). Related: Moping; mopey.
1956, from Swed. (c.1952), from (tramp-cykel med) mo(tor och) ped(aller) "pedal cycle with engine and pedals" (the earliest versions had auxiliary pedals).