Languishing, sickly.

Of a person, animal, bodily function, etc.: weak, faint, or inert, esp. from illness or fatigue; lacking vitality or vigour, listless. Also in…

poetic. Languid.

Of persons and their temperaments: Having the characteristics (flabby muscles, pale skin, sluggishness of vital and mental action) formerly…

Medicine. Of an organ, esp. the heart: functioning (or thought to be functioning) at a rate that is lower than normal. Cf. sense 4c.