Antonyms of adj arrhythmical

1 sense of arrhythmical

Sense 1
arrhythmic, arrhythmical -- (without regard for rhythm)

INDIRECT (VIA unrhythmical) -> rhythmical, rhythmic -- (recurring with measured regularity; "the rhythmic chiming of church bells"- John Galsworthy; "rhythmical prose")

Similarity of adj arrhythmical

1 sense of arrhythmical

Sense 1
arrhythmic, arrhythmical -- (without regard for rhythm)
       => unrhythmical (vs. rhythmical), unrhythmic -- (not rhythmic; irregular in beat or accent)