Footstep sound

It means the sound of footsteps. In 跫然 and 跫音, someone hears steps; the character gives the sound, not the visitor’s identity or intent.

The Zhuangzi, a classical Chinese philosophical text, tells in its “Xu Wugui” chapter of a solitary man glad to hear a footstep. In later Chinese idioms such as 空谷足音 and 空谷跫音, that sound can stand for a rare welcome visitor, message, or insight after isolation. Japanese uses 跫然 as literary wording for footsteps and 空谷の跫音 for welcome news or company.

What does 跫 mean in a message?

Read it as literary footstep imagery; the phrase sets the mood. If someone sends 跫 alone, there is not enough to infer warmth, loneliness, or who might be arriving; ask what phrase they mean.

The welcome belongs to expressions such as 空谷足音, not to 跫 by itself. In ordinary chat, a lone 跫 reads as a deliberate literary flourish.