lackluster

Etymology

From lack + luster.

adj

1. Lacking brilliance or intelligence.
2. Having no shine or lustre; dull.
3. (figurative) 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[.] 2016-12-30, Jordan Hoffman, “Gold review – the priciest ore is a bore in Matthew McConaughey misfire”, in The Guardian
   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). 19 May 2019, Alex McLevy, “The final Game Of Thrones brings a pensive but simple meditation about stories (newbies)”, in The A.V. Club
   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. 2020-06-29, Patrick Wintour, “UK criticised for 'lacklustre' response to Israel West Bank plans”, in The Guardian
   Tory MPs said Raab had been “lacklustre”, with one saying his position was “untenable”. 2021-08-20, Martin Farrer, “Friday briefing: ‘Lacklustre’ Raab under pressure to quit”, in The Guardian

noun

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