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

lower one’s ears • prick up one’s ears
lower one’s ears —(coll.) get a haircut (also: get one’s ears low-
ered): I’m debating weather or not to lower my ears before
school, leaning towards the more hippie of the options.
prick up one’s ears —(coll.) become attentive or alert to listen:
A bleating sound caught Baldred’s attention. He pricked up
his ears as it grew louder.
lower world • underworld
lower world —
1
. mortal earth as opposed to heaven: Innu-
merable high-dressed gentlemen, gods of this lower world, are
gone all to inorganic powder. 2. the realm of the dead: In the
mysteries of Eleusis, the return of Cora from the lower world
was regarded as the symbol of immortality.
underworld —
1
. the community of criminals: He was known
in the underworld circles as a luxury loan shark, lending
money to casino gamblers. 2. = lower world 2: Auernus was
the name of a deep lake near Puteoli, the reputed entrance to
the underworld.
Note: 
The compound does not correlate in meaning with the
phrase down under world—(coll.) Australia or New Zealand:
Things have been busy in the down under world I have been
in recently. I have flown back and forward between Australia
and New Zealand…
luck it out • one’s luck is out
luck it out—(also: luck out) achieve success by good luck in
a difficult situation: Rock City isn’t the easiest of places to
find if you don’t know Nottingham but somehow we lucked
it out.
one’s luck is out—one has bad luck: Such are the perils of
any racing these days, but I did begin to wonder if our luck
was out again.
lucky man • man of luck
lucky man —
1
. a man who is fortunate or successful: If he’s
a friend of yours, you’re a lucky man, for if ever a fellow was
one of the salt of the earth, he is. 2. a bridegroom: The six
gentlemanly cowboys swore that whoever should prove to be
the lucky man, the others would ush for him at the ceremony.
man of luck — = lucky man 
1
: I’m not known as a man of
luck. In fact, if anything can go wrong with me it usually
does!