5 letters · 11 points in Scrabble
adverb to a severe or serious degree
adverb (`ill' is often used as a combining form) in a poor or improper or unsatisfactory manner; not well
adverb evilly or wickedly
originFrom Middle English badly, baddely, baddeliche, equivalent to bad + -ly.
Etymology from Wiktionary, CC BY-SA 3.0