にっこり
にっこり · nikkori · JLPT N3 · adverb
smile
😊 Mimetic word from にこにこ (niko-niko, beaming); the っ…り form means one smile
Japanese makes sound-symbolic words in pairs: doubled にこにこ is ongoing beaming, while the っ + り form (like にっこり) marks one complete action. So にっこり is a single warm smile, often used as にっこり笑う.