Definitions:

1. evilly or wickedly adverb
   • We treated our parents badly on occasion.
2. in a disobedient or naughty way adverb
   • They behaved badly in school.
3. to a severe or serious degree adverb
   • fingers so badly frozen they had to be amputated
4. with great intensity (`bad' is a nonstandard variant for `badly') adverb
   • the injury hurt badly
5. with unusual distress or resentment or regret or emotional display adverb
   • they took their defeat badly
6. without skill or in a displeasing manner adverb
   • The subpar author writes badly.

Synonyms:

• bad
• disadvantageously
• heaps
• ill
• mischievously
• severely