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

on the wing • on wings
on the wing —
1
. (of birds) in flight: They spend at least nine
months of the year continuously on the wing. 2. in motion;
moving swiftly: Pope’s constitutional irritability kept him con-
stantly on the wing.
Note: 
The expression does not correlate in meaning with the
phrase on a wing and a prayer— relying on good fortune with
only the slightest hope of succeeding: It appears like the company
is running on a wing and a prayer in the month of Decem-
ber.
on wings —in a joyously exuberant mood: They sealed the
promise with a long loving kiss, and Gerard went home on
wings.
Note: 
The expression does not correlate in meaning with the
phrase with wings—(coll.) used of food to be taken home or out-
side from a restaurant: “Can I take your order?” “I’ll have a Big
Mac, a large fries and a Coke — with wings.”
on the wrong side of the tracks • on the wrong
track
on the wrong side of the tracks —(also: on the other side of the
tracks) in the less respectable or the poorer part of a town: We
went to a school which was on the wrong side of the tracks,
and we all got a fine education.
Note:
The expression is not antonymous in meaning to the
phrase on the right side of the hedge— on the advantageous or
winning side: The French thought themselves on the right side
of the hedge, but it proved otherwise.
on the wrong track —(also: on the wrong tack) thinking or
acting incorrectly: They won’t get it figured out because they
are on the wrong track.
on top • up top
on top —
1
. resting on smth.: An imposing enamel teapot
stands on top, quietly stewing. 2. in the lead; winning: The
horse that everyone had expected would be on top actually
came in third. 3. (also: at the top) in a position of power or
authority: The men on top are always trampling down those
who are trying to climb up.
up top —
1
. = on top 3: If you need more proof that the men
up top are ignoring our needs, the Government Accounting
Office has just released a new study. 2. (Air Force) in the sky:
You reveal your position to the aircraft up top and it is time
to move fairly fast. 3. (sl.) in terms of mental capacity: Peg,
you’ve got enough up top for both of us.