n.
Pronunciation: ' rä-k ə r
Function: noun
Date: 1760
1 a : either of two curving pieces of wood or metal on which an object (as a cradle) rocks b : any of various objects (as a rocking chair or an infant's toy having a seat placed between side pieces) that rock on rockers c : any of various objects in the form of a rocker or with parts resembling a rocker (as a skate with a curved blade) d (1) : any of the curved stripes at the lower part of a chevron worn by a noncommissioned officer above the rank of sergeant (2) : the curved stripe at the upper part of a chevron worn by a chief petty officer
2 : any of various devices that work with a rocking motion
3 : a rock performer, song, or enthusiast
– off one's rocker : in a state of extreme confusion or insanity <went off her rocker, and had to be put away ― Mervyn Wall>