Pessimistic, gloomy (8)
This clue is a double definition.
'pessimistic' is the first definition.
(I've seen this before)
'gloomy' is the second definition.
(I've seen this in another clue)
(Other definitions for downbeat that I've seen before include "Depressed - relaxed" , "Low-key" , "Casual" , "Miserable; relaxed" , "Gloomy; laid-back" .)
This clue is a double definition.
'pessimistic' is the first definition.
(associated in meaning)
'gloomy' is the second definition.
(thesaurus)
(Other definitions for negative that I've seen before include "Film with images reversed" , "Pessimistic, discouraging" , "Less than zero quantity" , "Less than positive" , "Avenge it for not being positive" .)