Spreading bile after a month, making some noise (7)
I believe the answer is:
decibel
'some noise' is the definition.
(I've seen this before)
'spreading bile after a month' is the wordplay.
'spreading' indicates an anagram.
'after' means one lot of letters go next to another.
'a month' becomes 'Dec' (abbreviation for December).
'bile' is an anagram of 'ibel'.
'ibel' put after 'dec' is 'DECIBEL'.
'making' acts as a link.
(Other definitions for decibel that I've seen before include "Measure of noise intensity" , "Noise unit" , "Unit of volume" , "Unit of measurement for loudness" , "Unit for measuring intensity of sound" .)