I noticed in conversation it is an ugly thing (7)
I believe the answer is:
eyesore
'an ugly thing' is the definition.
(I've seen this before)
'i noticed in conversation' is the wordplay.
'i' becomes 'eye' (I've seen this in other clues).
'noticed' becomes 'saw' (I've seen this in another clue).
'in conversation' indicates a 'sounds like' (homophone) clue.
'saw' sounds like 'sore'.
'eye'+'sore'='EYESORE'
'it is' acts as a link.
(Other definitions for eyesore that I've seen before include "pigsty" , "Horrible sight" , "bad sight" , "Blot on the landscape" , "Ugly object, hard on the sight" .)