De

De  

is a push through.

Degiri  

Typically a push through is responded by White, and a cut by Black follows. See push cut.

Tsukinuki  

If White tenuki for some reason and Black plays on a subsequent turn, the move is called a tsukinuki ツキヌキ　(penetrate through). White is in bad split shape.

Yurumeru (verb)  

When degiri above is too severe, White may allow tsukinuki by defending one side ( is yurumeru in Japanese). Marked white stones are probably sacrificed.