Dull

fosco

(cloudy, overcast)

monotono

(boring, not exciting or interesting — see also boring)

noioso

(boring, not exciting or interesting — see also boring)

nuvoloso

(cloudy, overcast)

opaco

(not shiny)

ottuso

(not bright or intelligent)

smussato

(lacking the ability to cut easily; not sharp)

soporifero

(boring, not exciting or interesting — see also boring)

spuntato

(lacking the ability to cut easily; not sharp)

tardo

(not bright or intelligent)

tedioso

(boring, not exciting or interesting — see also boring)

smussare

(to render dull)