overfull

Overfull is an adjective used to describe something that is filled beyond its capacity or beyond a desired boundary. The term is commonly used in contexts where limits matter, such as typography, page layout, packaging, and data handling.

In typesetting and computer printing, overfull is most often associated with the TeX family of systems (TeX, LaTeX). An overfull hbox occurs when the contents of a line cannot be broken to fit within the defined line width, causing the line to extend past the right margin. TeX reports this as an overfull or underfull box in the log, and the visible result may be text protruding into the margin or uneven justification. Common causes include long, unbreakable words or strings (such as URLs), insufficient hyphenation, or tightly constrained line widths. Remedies range from inserting discretionary breaks or adjusting hyphenation patterns to enabling microtype features, relaxing line-wrapping rules (for example, using \sloppy), or widening margins.

Outside typography, overfull describes any resource or container that has exceeded its capacity. For example, an overfull memory buffer or an inventory item set beyond storage limits indicates overflow. In user interface and web design, overflow-related issues are addressed with layout and rendering rules to prevent content from rendering outside its designated area, using strategies that manage or contain overflow.

See also: overflow, hbox, box model, pagination, hyphenation.