What does the expression "for crying out loud" mean and where does it come from?
Minced oaths are a sub-group of euphemisms used to avoid swearing when expressing surprise or annoyance.
Used to express frustration, exasperation, or annoyance.
In the Wiktionary there are a lot of synonyms 'for crying out loud'. I don't think that 'for crying out loud' means 'for Christ's sake'. I think that it is an expression in its own right. While 'for Christ's sake' is offensive, 'for crying out loud' is not.
What does it actually mean?
If you hurt yourself when doing a job, then to say 'Shit!' is understandable.
If in these circumstances, someone shouts out 'sugar', 'sugar' is understood to mean 'Shit', without saying shit.
People replace the word Shit with the word Sugar, because they both begin with a similar sound.
There is probably a similar mechanism 'for ....'. People start off by saying 'for - Christ's sake' and then switch to the more acceptable ' for - crying out loud'.
You could say this is an example of a snowclone, where a familiar phrase is given a slightly different meaning. (I have seen the explanation of snowclone, and it is slightly confusing.)
Because 'for crying out loud' is a substitute for something else, it is difficult to find its meaning. Whereas, if you said 'for Christ's sake', it would be clear that this was an appeal for divine intervention.
What the hell does "Suffering Sucatash" mean???
There is an explanation of this from another forum which is now closed. The explanation is essentially the same as the explanation above. However it does introduce a new word - malapropisms.
There was a rejection of Profanity in the mid 1800's, Victorian Age, so the common people developed a wide variety of malapropisms to avoid swearing on Holy names.