Green’s Dictionary of Slang

(US) well-dressed; thus dike up, to dress up.

1856		B.H. Hall College Words (rev. edn) 160: diked. At the University of Virginia, one who is dressed with more than ordinary elegance is said to be diked out. Probably corrupted from the word decked, or the nearly obsolete dighted.
1874		Whig & Tribune (Jackson, TN) 5 Dec. 3/4: The Gents of jackson [...] want to be diked up in the latest style.
1885		Semi-wkly Interior Jrnl (Stanford, KY) 21 July 3/3: Especially was it amusing to see Dan E. O’Sullivan, diked up as a fair maiden.
1890		Semi-wkly Interior Jrnl (Stanford, KY) 23 Dec. 3/2: A majority of the visting members were ‘diked up’ in their handsome uniform rank suits.
1894		Star-Gaz. (Elmira, NY) 15 May 4/3: Yale College Slang [...] Williams was diked out to beat the band and was bound for a skirt party somewhere.
1899		Virginian Pilot (Norfolk, VA) 8 Deb. 11/2: He was all ‘diked up’ in new clothes.
1901		W. Irwin Love Sonnets of a Hoodlum XIX n.p.: The more my sourballed murmur, since I’ve seen [...] Mame and Murphy, diked to suit the part, And clinching fins in public, heart-to-heart.
1906		J.W. Carr ‘Words from Northwest Arkansas’ in DN III:ii 133: dike out, v. phr. To dress up. ‘She was all diked out for the party.’.
1906		Sun (NY) 9 Sept. 1/3: The green diked Algy handed me that [...] stare of keen disappopintment.
1908		N.Y. Tribune 23 Aug. 37/3: I seen her in town the other day, all diked up, with ribbons an’ things.
1908		L.W. Payne Jr ‘Word-List From East Alabama’ in DN III:iv 305: diked up (or out), adj. phr. ‘He was all diked up in his best clothes.’.
1919		Van Loan ‘The Bone Doctor’ in Score by Innings (2004) 361: He was all diked up with a lot of cheap jewelry.
1922		Keowee Courier (Pickens Court House, SC) 30 Aug. 6/2: All local members had ‘diked up’ in their desbt.
1921		Richmond Times (VA) 25 Sept. 5/4: One will be proud to own one’s friend all diked up in one of those nobby two-tone silk bath robes.
1927		C. Woofter ‘Dialect Words and Phrases from West-Central West Virginia’ in AS II:8 352: He was all diked out for the party.
2009		L. McIlvanney All the Colours 43: I actually liked wearing a shirt and tie – getting dickered up, as Mum called it.