Function: kill-visual-line

Kill the rest of the visual line.
With prefix argument ARG, kill that many visual lines from point.
If ARG is negative, kill visual lines backward.
If ARG is zero, kill the text before point on the current visual

If you want to append the killed line to the last killed text,
use C-M-w before C-k.

If the buffer is read-only, Emacs will beep and refrain from deleting
the line, but put the line in the kill ring anyway. This means that
you can use this command to copy text from a read-only buffer.
(If the variable `kill-read-only-ok' is non-nil, then this won't even beep.)