feeble - weak
Something or somebody described as ‘feeble’ is without energy, strength, or power. In the case of a person, that is often due to age or illness. For that reason, the term is frequently used in association with someone elderly. ‘Feeble’ can also be used to insult somebody’s intelligence (‘feeble-minded’). The word ‘enfeeble’ means to make feeble.
Jack is no threat to anyone. He’s just a feeble old man.
Such was the feebleness of her argument, nobody took what Susan said seriously.
Repeated budget cuts have left the organization in an enfeebled state.