do someone's dags meaning (obsolete): definition

do someone's dags

noun

Etymology From darings.

UK, Obsolete, Slang To defy someone by doing something that they are unable to do.

"Can you climb?" asked Gale of Joe. "Like a monkey." "Of course," said Gale, drily, "very much like a monkey." "That's one to you; but I can do your dags." "You can't." "I can — anybody's dags. Look here."1880, Our Boys' Paper, page 411:
[…] do his dags for him, Billy would, if he could get at him. Wouldn't you, Billy?1914, William De Morgan, When Ghost Meets Ghost, page 575: