The expression shooting fish in a barrel is an idiom with an unknown origin. We will examine the meaning of the idiom shooting fish in a barrel, where it came from, and some examples of its idiomatic usage in sentences.
Shooting fish in a barrel is an idiom that describes something extremely easy to accomplish, something with one hundred percent chance of success. The image is a wooden barrel crammed full of live fish so that a gunshot anywhere in the barrel will hit at least one fish, probably many more. The expression shooting fish in a barrel came into use in the United States sometime around the turn of the twentieth century. Shooting fish in barrels was not an actual practice. The phrase is often rendered as a simile: like shooting fish in a barrel. A simile is a phrase used in a sentence that is a comparison of one thing with something else using the word like or the word as.
I pulled into the supply area and talked to a guy in the tower and he said the enemy came up that drainage ditch and it was like shooting fish in a barrel and there was half a body laying there. (The Examiner Enterprise)
OK, this is like shooting fish in a barrel: A Lada Samara is of course going to appear on the worst cars list of any road tester who’s driven one. (Motortrend Magazine)
Trying to predict the long-range summer weather is not exactly “shooting fish in a barrel.” (Martha’s Vineyard Times)