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derailleur

1 ENTRIES FOUND:
derailleur /dɪˈreɪlɚ/ noun
plural derailleurs
derailleur
/dɪˈreɪlɚ/
noun
plural derailleurs
Britannica Dictionary definition of DERAILLEUR
[count]
: a part on a bicycle that is used to change gears by moving the chain from one gear to another one see picture at bicycle