infirm

adjectives

lacking bodily or muscular strength or vitality

"a feeble old woman"; "her body looked sapless"

debile, decrepit, feeble, infirm, rickety, sapless, weak, weakly

is derived from

lacking firmness of will or character or purpose

"infirm of purpose; give me the daggers" - Shakespeare

infirm

is similar to

uncertain how to act or proceed

"the committee was timid and mediocre and irresolute"