Green’s Dictionary of Slang

blug n.

[SE blood + plug; the link to the definition remains unresolved]

(US campus) a stylish, socially admirable individual.

[US]W.C. Gore Student Sl. in Cohen (1997) 8: blug n. [Perhaps a contamination of blood and plug (both of the same meaning).] One who is very stylish, or who has a good position in society.