Low-key.
Low-key.
Describing something as 'low-key' means it is subtly expressed or deliberately understated. Perhaps deriving from musical terminology where 'key' refers to intensity, calling something low-key suggests it doesn't seek to attract attention and remains somewhat under the radar, yet it holds a unique appeal or importance.
Their wedding was a low-key affair with close friends.
Their wedding was an intimate and simple affair.
I prefer low-key vacations, avoiding crowded tourist spots.
I prefer simple and quiet vacations, avoiding crowded places.
They planned a low-key celebration with family.
They planned a small and understated celebration with family.