1. With unaffected simplicity.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• nnicely,
• nively,
• nativly,
• nawvely,
• naiviety,
• naivee,
• nievely,
• havely,
• niely,
• savely,
• naimly,
• narely,
• niavely,
• sively,
• naiivety,
• naivity,
• naivaty,
• naiveity,
• naisaly,
• naivly

• naval,
• navel.

The adjective form of the word "naively" is "naive".