Entry 1 sense Webster, 1913 Rhythmer /(rĭth"mẽr [or] rĭt͟h"-)/ · Rhyth·mer · IPA /ˈɹɪðəmə(ɹ)/ 01 n. One who writes in rhythm, esp. in poetic rhythm or meter. 1. One who writes in rhythm, esp. in poetic rhythm or meter.[R.] “One now scarce counted a rhythmer, formerly admitted for a poet.” — Fuller.