A dictionary of Confusable Phrases: More Than 10,000 Idioms and Collocations

kill the clock • kill time
kill the clock —(Sport) keep the ball away from the opposing
team at the end of a game so that they cannot score: The
Warthogs kept passing the ball back and forth among them
so as to kill the clock.
kill time —do smth. which is not very interesting while one
is waiting for time to pass: We then went over to the record
shop just to kill time.
See also: kill-time / killing time.
kill-time • killing time
kill-time —an occupation which is not very useful or inter-
esting, intended to pass away the time: It was such an utter
loss to the reader, that he could not so well call it passtime as
kill-time.
killing time —said of the time at which an animal is fit to
be killed: Hog killing time is a season of severe and lasting
cold weather, required for the preserving of the meat.
See also: kill the clock / kill time.
king bird • king of birds
king bird —an American tyrant flycatcher (Tyrannus caroli-
nensis): If you ever saw a crow with a king bird after him, you
will get an image of a dull speaker and a lively listener.
king of birds —said of the eagle: The strength, keen vision,
graceful and powerful flight of the eagle are proverbial, and
have given to him the title of the king of birds.
Note: 
Neither expression correlates in meaning with the phrase
king’s bird
—(also: king bird of paradise) a bird of the genus
Paradisea: The king’s bird is carried in the procession, and the
yelling and chatting of the marketers is heard above anything.
King Charles’s head • King’s head
King Charles’s head —a subject that keeps on appearing in a
person’s conversation: He talks about nothing but money —
it’s becoming a King Charles’s head!