Fetching details from the dictionary...

enough; too many; too much
「沢山」 has another reading with different meanings.
もうお菓子は沢山食べたよ。
I've already eaten enough sweets.
言い訳はもう沢山だと思った。
I thought I'd had enough of excuses.
お土産はもう沢山ですので気にしないで。
I've had enough souvenirs, so please don't worry about it.