1. Lack of knowledge or mental capacity; idiocy; foolishness 
2. An idiom; a form, mode of expression, or signification, peculiar to a language

Derived forms: idiotisms

• surtax
• surtitle
• surtout
• surveil
• ibidem
• ibis
• Ibis ibis
• Ibizan hound
• Ibizan Podenco
• Ibn al-Haytham
• ibn Talal Hussein
• ibn-Roshd
• ibn-Sina
• ibolium privet
• ibota privet
• Ibrahim
• IBRD
• Ibsen
• Ibsenian
• ibuprofen
• ic
• icaco
• ICAO
• Icarus
• ICBM