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

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

• 糸(silk thread; filament)
• 龶(coarse undyed thread bundle; top part of thread)

Raw silk that hasn't been dyed suggests the meaning of pure, simple, and basic.

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

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

• 糸(silk thread; filament)
• 龶(coarse undyed thread bundle; top part of thread)

Raw silk that hasn't been dyed suggests the meaning of pure, simple, and basic.