Meaning of “dull” - Learner’s Dictionary

dull

adjective uk us /dʌl/
BORING

B1 not interesting:

a dull place
a dull person
NOT BRIGHT

not bright:

dull colours
dull weather
SOUND

A dull sound is not loud or clear:

a dull thud
PAIN [ always before noun ]

A dull pain is not strong:

a dull ache
dullness noun [ U ]
dully adverb

(Definition of “dull adjective” from the Cambridge Learner’s Dictionary © Cambridge University Press)