Green’s Dictionary of Slang

(US) boring.

1964		M. Braun Love Me Do 14: ‘We had a great hip English master and instead of keeping us to the drag stuff [...] he would let us read Tennessee Williams’.
1968		‘Hy Lit’ Hy Lit’s Unbelievable Dict. of Hip Words 30: party pooper – A drag person; a cat or bird who is not a swinger.
1971		M. Novotny Kings Road 80: ‘I know she’ll bore you but just treat her as a joke.’ ‘She’s a real drag doll’ moaned CB.
1983		Eble Campus Sl. Mar. 2: drag – boring, uninteresting.