Bump
White bumps into the Black stone. A natural local response is usually to stretch to a or b. A common term for this move is butting play.
The Japanese term is tsukiatari.
The butting play is not a very usual move, but it has its uses. There is an interesting branch of 3-4 point joseki (invented by Kitani Minoru) starting with a bump:
![[Diagram]](../../diagrams/22/deede03479776b52f3ad654f74e417ec.png)
Kitani joseki - a,b are miai
Also, the first round of Go Seigen vs Miyamoto Naoki 9x9 match started with a bump: