fonts/cc-by-sa/knowledge/glossary/terms/regular_upright/content.md

“Regular” can refer to the regular weight, usually assigned the font-weight value of 400 in CSS, or the regular/upright (i.e., non-italic or oblique) style of a typeface.

When referring to the style—that is, whether the typeface is changing between and upright and italic (or oblique)—it’s usually best to add clarity by referring to the Regular as “upright” type. However, note that in CSS, the upright style is referred to as “normal”; i.e., font-style: normal;.

“Regular” might also refer to type’s width when there are condensed or wide variants available, although this is not often named explicitly.