Na-adjective (keiyodoshi)
smiling; beaming; radiant; bright; cheerful
Usually written using kana alone
「怒ってない。ほら見て、このにこやかな笑顔」「それは作り笑いっていうんですよ」"I'm not angry. Look, see this smiling face?" "That's what they call a forced smile!"
Also written 柔やか【にこやか】