vague (Adjective) — Not clearly understood or expressed. ex. "their descriptions of human behaviour become vague, dull, and unclear" ex. "vague...forms of speech...have so long passed for mysteries of science"
vague (Adjective) — Not precisely limited, determined, or distinguished. ex. "vague feelings of sadness" ex. "a vague uneasiness"
vague (Adjective) — Lacking clarity or distinctness. ex. "saw a vague outline of a building through the fog"