infirm

 
Pronunciation: /ɪnˈfəːm/

adjective

  • not physically or mentally strong, especially through age or illness: those who were old or infirm elderly and infirm people (as plural noun the infirm) care for the infirm
  • archaic (of a person or their judgement) weak; irresolute: he was infirm of purpose

Derivatives

infirmly

adverb

Origin:

late Middle English (in the general sense 'weak, frail'): from Latin infirmus, from in- 'not' + firmus 'firm'