Adventure could be the odd one because it has a different meaning/category than the other words
Noun could be the odd one because it is the only word not starting with "ad"
Adjective could be the odd one because it is the only word with dots ("j" and "i")
unlike all the other words, I can't find a single reason why Adverb would be odd...
for this reason it must be Adverb 0_o
Very similar answer to mine, very nice!! =)
adventure