内线消息

• 冂(outer boundary; fence)RADICAL
• 入(enter; go in)ASSOCIATIVE

Inside a fence, something that has already gone in becomes what is enclosed.

• 糸(thread; silk)RADICAL
• 泉(stream; water)PHONETIC

A thin thread flows like a small stream running long and continuously.

• 氵(water; liquid)RADICAL
• 肖(resembling; diminishing)PHONO-SEMANTIC

Water gradually drips away and disappears, that is the meaning of the character tiêu.