Is there an idiom available, that is exactly opposite to "Cake walk" or "Child's play"? [closed]
Solution 1:
You could say, "It was no small feat," and mean that it was actually a very great or difficult feat. [Wiktionary] This understated way of emphasizing something is called litotes.
A herculean task is one that is all but impossible. Merriam-Webster explains,
The hero Hercules, son of the god Zeus by a human mother, was famous for his superhuman strength. To pacify the wrath of the god Apollo, he was forced to perform twelve enormously difficult tasks, or "labors". These ranged from descending into the underworld to bring back the terrifying dog that guarded its entrance to destroying the many-headed monster called the Hydra. Any job or task that's extremely difficult or calls for enormous strength is therefore called herculean.
Solution 2:
You could describe such a problem using the idiomatic phrase:
A hard/tough/difficult nut to crack
Cambridge Online Dictionary defines the idiom as follows:
A problem that is very difficult to solve or a person who is very difficult to understand.
Collins Online provides two different definitions:
- a person not easily persuaded or won over
- a thing not easily understood
The Free Dictionary provides the following definition and example:
A difficult problem to solve
Example: A company whose product has sold well in the States may find the European market a tougher nut to crack.
Solution 3:
May not be an exact opposite but you may be able to call it an uphill battle/fight/struggle.
TFD(idioms):
an uphill battle/fight/struggle (also an uphill job/task)
if something you are trying to do is an uphill struggle, it is very difficult, often because other people are causing problems for you
We're trying to expand our business, but it's an uphill battle.
Cambridge Idioms Dictionary, 2nd ed. Copyright © Cambridge University Press 2006. Reproduced with permission.
Solution 4:
A more creative alternative if you like its tone would be this idiom:
One does not simply [...your action here...] .
...coming from the well known "One does not simply walk into Mordor.". Original meme for reference:
Obviously, "walking into Mordor is not child's play" :)