1. Not clearly expressed or understood
   "their descriptions of human behaviour become vague, dull, and unclear"; "vague … forms of speech … have so long passed for mysteries of science";
   - obscure
    
2. Not precisely limited, determined, or distinguished
   "vague feelings of sadness"; "a vague uneasiness";
   - undefined
    
3. Lacking clarity or distinctness
   "saw a vague outline of a building through the fog";
   - dim, faint, shadowy, wispy

Derived forms: vaguer, vaguest

See also: indefinable, indefinite, indistinct, muddy, unclear, undefinable

Encyclopedia: Vague