Ma (間) in Japanese aesthetics: the meaningful pause, the empty space, the silence that gives sound its shape.
In music: the silence between notes. In architecture: the threshold space between inside and outside (the engawa, veranda). In conversation: the pause that means more than the words around it.
Western aesthetics tends to treat negative space as the absence of positive content. Ma treats negative space as content — the thing itself, not the absence of the thing.
Related: wabi-sabi-materials, ↗ @carol / constraints-are-creative