Wikipedia
Lampriformes is an order of ray-finned fish. Members are collectively called lamprids (which is more properly used for the Lampridae) or lampriforms, and unite such open- ocean and partially deep-sea Teleostei as the crestfishes, oarfish, opahs, and ribbonfishes. A synonym for this order is Allotriognathi, while an often-seen, but apparently incorrect, spelling variant is Lampridiformes. They contain seven extant families which are generally small but highly distinct, and a mere 12 lampriform genera with some 20 species altogether are recognized.
The scientific name literally means "shaped (like the) bright (one)", as "lampr-", meaning bright, comes from lampris, the generic name for the opah. In contrast, most other living lampriforms are actually ribbon-like and not very similar to the disc-shaped opahs in habitus. They are, however, quite distinctly united by their anatomy, and the family's phylogeny, as well as the most ancient fossils of this order suggest the original lampriform was rather "opah-shaped". The scientific name is a combination of Lampris (the type genus) + the standard fish order suffix "-formes". It ultimately derives from Ancient Greek lamprós (λαμπρός, "bright") + Latin forma ("external form"), the former in reference to brilliant coloration of opahs.