1.Definition: lacking bodily or muscular strength or vitality

"A feeble old woman"

Related Adjective(s):debile, decrepit, infirm, rickety, sapless, weak, weakly

2.Definition: lacking strength

Related Adjective(s):nerveless

3.Definition: lacking strength or vigor

"Feeble efforts", "A feeble voice"

Related Adjective(s):faint

4.Definition: pathetically lacking in force or effectiveness

"A feeble excuse"

Related Adjective(s):lame