Green’s Dictionary of Slang

(US, Southern) a sweetheart.

1869		‘South-Western Sl.’ in Overland Monthly (CA) Aug. 131: I knew a man in Texas once who had no more sense than to have a ‘jimpsecute,’ and this was all her name: Dionysia Boadicea Jeffalinda Jacobina Christiana Buckiana Caledonia Susannah Emily Wyatt Wilkinson Moore Wynnle!
1870		London Figaro 1 Dec. n.p.: The jimplecute of Texas changed her name, which was a good thing to do – jimplecute being Texas vernacular for sweetheart [F&H].