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

kiss it off • kiss off
kiss it off —(coll.) not deal with smth.; put it off: Every
hostage negotiation includes tense moments when one doubts
the other side is operating in good faith and is tempted to kiss
it off.
kiss off —is used to rudely tell a person to go away (and stop
being annoying ): That was before the time when women
would have told him to kiss off in public. It wouldn’t go
unchallenged these days.
knight of the pen • knight of the pencil
knight of the pen —(liter. or joc.) a writer or a journalist:
Kolosimo became the knight of the pen in the sixties and sev-
enties. Millions of readers were immersed in the mysteries of
the universe by reading his books.
knight of the pencil —(UK derog.) 
1
. a bookmaker: We have
mentioned the knights of the pencil. Bookmakers are not per-
mitted to take up positions at will on racecourses under Grey-
hound Racing Association jurisdiction. 2. an artist; a car -
toonist: The shameless knights of the pencil found it easy to
caricature the spare, bent figure and bushy locks when getting
off jokes about professors.
knock heads together • put heads together
knock heads together —get people to stop quarrelling and
behave sensibly by taking firm action: An elected mayor is
empowered to knock heads together and persuade people who
traditionally don’t talk to each other to do so.
put heads together —(also: lay heads together) have a discussion
in order to solve a problem, etc.: The present plans are far too
expensive. I think we should put our heads together and see
if we can somehow make them cheaper.
Note: 
The expression does not correlate in meaning with the
phrase get one’s head together—(coll.) get mentally organized;
start to perform efficiently (also: get one’s act together): It has
taken me over ten years to get my head together enough to
put this down in writing, but I have carried it in my heart.