1. In a manner disapproved or not allowed by custom
   - illegitimately 
2. In an illegal manner
   - illegally, lawlessly

See also: illicit

Antonym: licitly

• unbelt
• unbelted
• unbend
• unbendable
• unbending
• unbeneficed
• unbent
• unbiased
• unbiassed
• unbidden
• unbigoted
• unbind
• unbitter
• unbleached
• unblemished
• unblended
• unblessed
• unblinking
• unblinkingly
• unblock
• unbloody
• unblushing
• unblushingly
• unbodied
• unbolt