出没无常

• 屮(sprout; bud)ASSOCIATIVE
• 凵(hole; mouth of a hole)ASSOCIATIVE

A sprout reaching up out of the ground hole is the meaning of 'come out' or 'emerge'.

• 氵(water; liquid; juice)RADICAL
• 殳(weapon; club)PHONETIC

Water pressing down and submerging everything like a stick striking downward causes things to disappear.

• 一(one; initial)ASSOCIATIVE
• 尢(disabled person; insufficient)ASSOCIATIVE

From the beginning there was a shortage, so 無 means 'nothing at all'.

• 尚(respect; also; still)PHONETIC
• 巾(cloth; fabric)RADICAL

A cloth scarf, always treasured and used daily, symbolizes something of constant value.