lackluster

adj

1. (US)Lacking brilliance or intelligence.
2. (US)Having no shine or luster; dull.

   “A faded, and an ancient dragon he was; and many a wintry storm of rain, snow, sleet, and hail, had changed his colour from a gaudy blue to a faint lack-lustre shade of gray.”

   “He sat looking at her with lack-lustre eyes. The light suddenly came back into them.”

3. (US, figuratively)Not exceptional; not worthy of special merit, attention, or interest; having no vitality.

   “The actor gave a lackluster performance in his latest film.”

   “An allegedly true story emerges as a lackluster riff on American Hustle and The Wolf of Wall Street with a scrappy turn from an overly disguised lead star[.]”

   “It’s fascinating to see a show wrap up in a manner wherein many of the flaws so clearly occur offscreen rather than on; the plague of season eight hasn’t been lackluster episodes, for the most part (though “The Last Of The Starks” was a definite low point).”

   “Pressure on the UK government to commit to concrete measures and not just “lacklustre” verbal condemnation if Israel goes ahead with annexation of parts of the West Bank has been stepped up by a coalition of 14 British charities and human rights groups.”

   “Tory MPs said Raab had been “lacklustre”, with one saying his position was “untenable”.”

noun

1. (US, uncountable)Lack of brightness or points of interest.
2. (US, countable)A person or thing of no particular brilliance or intelligence.