Green’s Dictionary of Slang

(US campus) to urge someone towards a relationship.

2014		C. Eble (ed.) UNC-CH Campus Sl. Spring 2014 Fall 6: SHIP — < relationship favor or advocate a romantic relationship between two people: ‘Elsa and Olaf should have gotten married. I ship them so hard’.
2024		Axis Parents’ Guide to Teen Sl. 🌐 Ship = Short for ‘relationship.’ Used to endorse/support a romantic coupling, even one that’s not reality. ‘I ship Ron and Hermione’.