1. Without formality
   "he visited us informally" 
2. With the use of colloquial expressions
   - colloquially, conversationally

See also: informal

Antonym: formally

• identification number
• identification particle
• identified
• identifier
• identify
• Identikit
• Identikit picture
• identity
• identity card
• identity crisis
• identity element
• identity matrix
• identity operator
• identity theft
• identity verification
• ideogram
• ideograph
• ideographic
• ideographically
• ideography
• ideologic
• ideological
• ideological barrier
• ideologically
• ideologist