Green’s Dictionary of Slang

1. especially interested or informed.

1830		J. Galt Lawrie Todd I Pt II 120: I ain’t special ’bout pedigrees; but my wife [...] wont have nobody call me but squire.
1960		S. Bechet Treat It Gentle 151: [H]e said, ‘Sidney, come on inside. My friend wants to see you.’ Well I knew better than that [...] So I said, ‘You tell your friend I’m not special about seeing him.’.

2. (US campus) unpleasant.

1988

Eble Campus Sl. Mar.

3. (US teen) odd and slightly interesting.

2005

A. Swartz ‘Sweet, Tight and Hella Stupid’ in S.F. University High School Update Mar.–Apr. 2: special – odd, interesting (but not very).