ed-kill-line (vi command: D, Ctrl-K; emacs: Ctrl-K, Ctrl-U) + Kill from the cursor to the end of the line.
Readline
kill-line (C-k) Kill the text from point to the end of the line. With a negative numeric argument, kill backward from the cursor to the beginning of the current line.
em-kill-line (not bound) Delete the entire contents of the edit buffer and save it to the cut buffer. vi-kill-line-prev
Readline
kill-whole-line (not bound) Kill all characters on the current line, no matter where point is.