kill-word). See section Words.
backward-kill-sentence). See section Sentences.
kill-sexp). See section Lists and Sexps.
A kill command which is very general is C-w
kill-region), which kills everything between point and the
mark. With this command, you can kill any contiguous sequence of
characters, if you first set the region around them.
A convenient way of killing is combined with searching: M-z
zap-to-char) reads a character and kills from point up to (and
including) the next occurrence of that character in the buffer. A
numeric argument acts as a repeat count. A negative argument means to
search backward and kill text before point.
Other syntactic units can be killed: words, with M-DEL and M-d (see section Words); sexps, with C-M-k (see section Lists and Sexps); and sentences, with C-x DEL and M-k (see section Sentences).
You can use kill commands in read-only buffers. They don't actually change the buffer, and they beep to warn you of that, but they do copy the text you tried to kill into the kill ring, so you can yank it into other buffers. Most of the kill commands move point across the text they copy in this way, so that successive kill commands build up a single kill ring entry as usual.