WordWeb Online

1. ('ill' is often used as a combining form) in a poor or improper or unsatisfactory manner; not well
   "the team played poorly"
   - ill, badly

1. Somewhat ill or prone to illness
   "feeling poorly"
   - ailing, indisposed, peaked, sickly, unwell, under the weather, seedy, out of sorts, off-colour [Brit], crook [Austral, NZ]

See also: ill, poor, sick