Japanese phrase
もういいです。 mō i i de su
Meaning
That's enough.
When to use it
Politely declines an offer of more of something. It is common when refusing another serving or stopping an activity, and it sounds softer than a blunt refusal.
Example dialogue
おかわりはいかがですか？ o ka wa ri wa i ka ga de su ka
Would you like another serving?
いいえ、もういいです。 i i e mō i i de su
No, that's enough.