a/the son of a gun

son of a gun

1. A mean or unpleasant man. Julie's ex-husband was such a mean son of a gun, it's no wonder she divorced him.
2. An emphatic expression of affection for a man one considers daring, mischievous, or tough. That son of a gun really pulled through for us when we needed him!
3. An inanimate object that is problematic. My car broke down, and I can't figure out how to fix the son of a gun!
See also: gun, of, son
Farlex Dictionary of Idioms.

son of a gun

 and son of a bachelor
a worthless person. (A substitute for son of a bitch.) That tightfisted son of a gun won't buy me a beer. He can be a real son of a bachelor when he's in a bad mood.
See also: gun, of, son
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

son of a gun

a humorous or affectionate way of addressing or referring to someone. informal
The term arose with reference to the guns carried on board ships: it is said to have been originally applied to babies born at sea by women accompanying their husbands.
See also: gun, of, son
Farlex Partner Idioms Dictionary

a/the ˌson of a ˈgun

(American English, informal, spoken) a person or thing that you are annoyed with: My car’s at the shop — the son of a gun broke down again.
See also: gun, of, son
Farlex Partner Idioms Dictionary

son of a gun

1. n. a despicable person, usually a male. (Euphemistic for son of a bitch.) If that son of a gun thinks he can boss me around like that, he’s got another think coming.
2. n. old buddy. I went to school with this son of a gun! He’s my old buddy.
3. exclam. I am totally surprised!; I am shocked! (Usually Son of a gun!) The thing just blew up! Son of a gun!
See also: gun, of, son
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions

son of a gun

A rogue or scoundrel. Some etymologists believe that this term, which originated about 1700, once meant the illegitimate son of a soldier (gun). Others, however, believe it simply was a euphemism for son of a bitch that appealed because of its rhyme. Still another theory, recorded in Smyth’s Sailor’s Word-Book (1867), is that it was originally applied to boys who were born at sea, in the days when women were permitted to accompany their sailor husbands, and alluded to a child being “cradled under the breast of a gun.”
See also: gun, of, son
The Dictionary of Clichés by Christine Ammer
See also:
  • son of a gun
  • son of a sea biscuit
  • son of a biscuit
  • son of a biscuit eater
  • I see what you mean
  • How do you mean?
  • mean to say
  • not mean diddly
  • hung up