vapid — lacking or having lost life, sharpness, or flavor; insipid; flat: vapid tea.
adjective flavorless
insipid — without distinctive, interesting, or stimulating qualities; vapid: an insipid personality.
anodyne — If you describe something as anodyne, you are criticizing it because it has no strong characteristics and is not likely to excite, interest, or upset anyone.
watery — pertaining to or connected with water: watery Neptune.
weak — not strong; liable to yield, break, or collapse under pressure or strain; fragile; frail: a weak fortress; a weak spot in armor.
boring — Someone or something boring is so dull and uninteresting that they make people tired and impatient.
