SLY is validvalid

crafty [adj SLIER, SLIEST, SLYER, SLYEST] : SLILY [adv], SLYLY [adv]

972 of 196,601 in NWL2023·also valid in CSW24

cunning, wily; surreptitious [adj SLIER or SLYER, SLIEST or SLYEST, SLILY or SLYLY]