The Collaborative International Dictionary of English v.0.48:
Incapacious \In`ca*pa"cious\, a. [Pref. in- not + capacious: cf. L. incapax incapable.] Not capacious; narrow; small; weak or foolish; as, an incapacious soul. --Bp. Burnet. -- In`ca*pa"cious*ness, n. [1913 Webster]