Definition of atonic in US English:



  • 1Linguistics
    (of a syllable) without accent or stress.

    • ‘In Portuguese, vowels have stressed (tonic) and unstressed (atonic) forms.’
    • ‘In this kind of metric versification, neither the actual number of the syllables nor the difference between tonic and atonic syllables had much importance.’
  • 2Physiology
    Lacking muscular tone.

    • ‘Atonic and tonic seizures are characterized by a sudden change in muscle tone.’
    • ‘In Poliomyelitis the greatest possible care must be taken to prevent bruising atonic muscle fibers.’
    • ‘The highest levels of intoxication can be life-threatening, producing delirium, coma, atonic bladder and cardiac arrhythmias.’