outer frame; border; outside margin
Refers to the outer frame or border of a physical object, document, or abstract structure. Often used in contexts like picture frames, table borders, or the outer limits of a system.
Please make the outer border of this table a thick line.
The outer frame of the picture is a little crooked.
Compound of 外 (そと, 'outside') and 枠 (わく, 'frame').