/ Dictionary / Index R rocker arm: Meaning and Definition of Find definitions for: rock'er arm" Pronunciation: [key] — Mach. Mach. a rocking or oscillating arm or lever rotating with a moving shaft or pivoted on a stationary shaft. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. rocker rocker panel Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language