Defn: Lacking in matter or substance; visionary; chimerical.

UNSUBSTANTIALIZE
Un`sub*stan"tial*ize, v. t. Etym: [1st pref. un- + substantialize.]

Defn: To make unsubstantial. [R.]

UNSUBSTANTIATION
Un`sub*stan`ti*a"tion, n. Etym: [1st pref. un- + substantiation.]

Defn: A divesting of substantiality.

UNSUCCEEDABLE
Un`suc*ceed"a*ble, a.

Defn: Not able or likely to succeed. [Obs.] Sir T. Browne.

UNSUCCESS
Un`suc*cess", n.

Defn: Want of success; failure; misfortune. Prof. Wilson.

UNSUCCESSFUL
Un`suc*cess"ful, a.