When software attempts to emulate an italic style, bold (or other) weight, ordinals, or small caps in lieu of actual font files for those variants, they’re referred to as “faux,” “fake,” “pseudo,” or “synthesized” italics (or bolds, etc.).

Typically this occurs in graphic design software when the user is attempting to use a bold weight (etc.) but doesn’t have that font installed (or activated) on their machine; or on the web where a website is attempting to render a bold weight (etc.) but isn’t actually serving that web font to end users.