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

Note:
The expression is not antonymous in meaning to the
phrase short dog—(U.S. sl.) a bottle of cheap wine: Every now
and then I get a short dog of Train and make my friends make
funny faces as they watch me drink it.
Big Grey Dog —(U.S. sl.) a Greyhound Lines, Inc. bus (Grey-
hound Lines, Inc. providing the major intercity bus transporta-
tion): Greyhound is as American as apple pie. You have not
lived unless you rode the Big Grey Dog, as I like to call it.
big drink • long drink
big drink —(U.S. sl.) the Atlantic ocean (also: big pond):
When you’re [flying] over the big drink you really get to feel
how tiny we humans are.
Note: 
The expression does not correlate in meaning with the
phrase big drink of water—(sl.) 
1
. a large body of water: Lake
Michigan is a big drink of water; the bacteria levels fluctuate
dramatically as you move around the shore. 2. (also: tall drink
of water) a tall person: All they knew was that the bank officer’s
killer was a big drink of water who looked like a mountain
man.
long drink —a cold refreshing drink served in a tall glass,
containing little or no alcohol: Facilities include a swimming
pool and a “beach shack” serving long drinks all day.
big game • large game
big game —
1
. the larger animals, such as lions, etc.: For big
game, Bushveld is that part of the Transvaal which the hunter
must seek. 2. an important sport event: Believe it or not, the
best players on your team get nervous before a big game. 3.
an adventurous undertaking involving great risk and gain: Just
look at my life, Luke. It’s all one big long game.
Note: 
The expression does not fully correlate in meaning with
the phrase great game—
1
. excellent performance in a sports event:
It was a great game that was tightly contested throughout. 2.
= big game 3: Disraeli was an adventurer who played the great
game va banque with a courage and effrontery…
large game — = big game 
1
: The country round is full of large
game, especially elephants, giraffe, and zebras.
See also: little game / small game.