[i]Ornamental braid or coat fastenings consisting of spindle-shaped buttons and loops.[/i]
[tn]— Oxford Languages dictionary[/tn]

That fancy (usually golden) braid you sometimes see on dress uniforms. Originally used to fasten coats and jackets, but some of the more elaborate ones (featuring fancy loops and extensive length) are purely ornamental. Napoleonic era military uniforms tend to feature extensive frogging. 

Some modern day parade dress and marching band uniforms still retain ornamental frogging. Several [[Umamusume]] characters feature frogging on their racing outfits; these outfits also tend to resemble parade dress uniforms (e.g. [[Symboli Rudolf (Umamusume)|]]'s).

[[Kantai Collection|Kancolle]]'s [[Kongou (Kancolle)|]]-class modified miko uniform also features frogging on the front (where it acts as a clasp holding the coat-like strips of cloth together). This is done in a shape resembling that of a sacred shimenawa rope.

Traditionally the Chinese [[tangzhuang]] (and some other Chinese clothes) are also fastened together using froggings, but it is best to avoid tagging such examples with frogging unless they are visually distinctive (i.e. thicker and/or more elaborate braids).
frogging