Green’s Dictionary of Slang

quick, speedy.

1890		Kipling ‘The Big Drunk Draf’ in Soldiers Three (1907) 32: Fetch my throlly, an’ six av the jildiest men, and run me up in shtyle.
1972		N. Conway Bloods 18: It was soon to be known as the jildiest battalion on the Curragh. [Ibid.] 124: The way we cut our leggings short to look more jildy [BS].