Smiling or beaming; having a pleasant, friendly expression or disposition.
店主はにこやかに客を迎えた。
The shopkeeper greeted the customer with a smile.
彼女はにこやかな笑顔で写真に写っていた。
She appeared in the photo with a beaming smile.
にこやかに話す人は印象が良い。
People who speak pleasantly leave a good impression.