I1N1S1U1F4F4E1R1A1B3L1E1
20 points
INSUFFERABLE is validvalid
not sufferable [adj] : INSUFFERABLY [adv]
not to be endured, also UNSUFFERABLE [adj INSUFFERABLY]
not sufferable [adj] : INSUFFERABLY [adv]
not to be endured, also UNSUFFERABLE [adj INSUFFERABLY]