1.Definition: lacking clarity or distinctness

"Saw a vague outline of a building through the fog"

Related Adjective(s):dim, faint, shadowy, wispy

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"

Related Adjective(s):obscure

3.Definition: not precisely limited, determined, or distinguished

"Vague feelings of sadness", "A vague uneasiness"

Related Adjective(s):undefined