岚 is a bound form (b.f.) meaning 'mist in the mountains' — it almost always appears as the second element in two-character words like 山岚 (mountain mist) or 岚烟 (misty haze). It has a literary, poetic flavor and is rarely used alone in modern conversation. If you translated the English gloss 'mist' back into Chinese, you'd likely produce 雾 (wù), the everyday word; 岚 specifically evokes the hazy air over wooded hills.