1.Definition: lacking clarity or distinctness
"Saw a vague outline of a building through the fog"
2.Definition: not clearly expressed or understood
"Their descriptions of human behavior become vague, dull, and unclear", "Vague...forms of speech...have so long passed for mysteries of science"
3.Definition: not precisely limited, determined, or distinguished
"Vague feelings of sadness", "A vague uneasiness"