INFIRM is validvalid

to weaken or destroy the validity of [v INFIRMED, INFIRMING, INFIRMS] : INFIRMLY [adv]

22,022 of 196,601 in NWL2023·also valid in CSW24

to weaken or destroy the validity of [v -ED, -ING, -S] / sickly [adj INFIRMER, INFIRMEST, INFIRMLY]