凡 is a bound form (b.f.) — it cannot stand alone and always appears as part of a compound word. It has three main clusters of meaning: (1) 'ordinary, commonplace' in words like 平凡 (píngfán, ordinary) and 非凡 (fēifán, extraordinary); (2) 'worldly, mortal' in words like 凡间 (fánjiān, mortal world) and 凡尘 (fánchén, the mundane world); (3) 'every, any, all' in words like 凡是 (fánshì, every/all) and 大凡 (dàfán, generally). The 'outline' sense (as in 大凡) is less common but also appears.