na-adjective, noun which may take the genitive case particle 'no', noun
essentially the same; much of a muchness
Used when things are nearly identical, with only trivial differences. Often appears in the phrase 大同小異だ or as a な-adjective.
どの候補者の政策も大同小異で、選ぶのに困る。
The policies of all the candidates are much the same, so it's hard to choose.
彼の説明は前回と大同小異だった。
His explanation was essentially the same as last time.