Five years before Shakespeare died Randle Cotgrave produced A dictionarie of the French and English tongues.  This is the document that the Oxford English Dictionary cites as the first use of the word omelet in English.

There is a kind of circular logic about this particular entry in that old dictionary.  What we are looking at here is a list of French words with English definitions, along with, as he puts it

Briefe Directions for such as desire to learne the French Tongue

So the entry for omelette spelled O M E L E T T E is an entry for a French word.  The definition uses the same word, as an English word, spelled O M E L E T to tell us what it is.

This is sort of confusing if indeed the word has never turned up in English before. I don’t suppose he was being subtle about the spelling.  Remember that around this time Shakespeare was spelling his own name in several different ways.

Anyway, it is this appearance in the definition, not in as the word being defined that qualifies it as the first citation.

Randle goes on to explain that an omelet is a “pancake of egges.”  Everyone knows that a pancake is flat.  It is the flat nature of this pancake of eggs that gave it its name “omelet.”  Our English word laminate means a thin layer and comes from a Latin root.  Through various twists and turns a Latin word meaning “a thin plate of metal” moved through French and into English, emerging as “omelet.”

At first I thought it was the plate of metal upon which the eggs were cooked that gave it its name, or perhaps the cooking implement, since one of these words also meant knife or blade.  But in fact it was the thinness of the omelet that invited the name.