• 夕(evening; night)
• 口(mouth; speech)

When it's dark and people can't see each other, they must use their mouth to call out names to recognize one another.

• 朿(sharp thorn; prickle)
• 刂(knife (radical))

Using a knife to stab into a sharp thorn—that is the action of piercing.

• 夕(evening; night)
• 口(mouth; speech)

When it's dark and people can't see each other, they must use their mouth to call out names to recognize one another.

• 朿(sharp thorn; prickle)
• 刂(knife (radical))

Using a knife to stab into a sharp thorn—that is the action of piercing.