DEARMAIZIE

An egg, for this context, is a reproductive body produced by a bird. An egg consists of an eggshell (the protective layer), a yolk (the yellow part) and albumen (the clear gooey stuff we call the white). We refer to the egg as the sum of its 3 parts.

An eggshell is the thin, hard outer part of an egg. Eggshells can be removed from eggs. The term breaking or cracking an egg is used for this action. After the gooey, messy part is extracted, you are left with a harmless piece of calcium carbonate. Crush it up and feed it to the birds or put it in the compost.

Walking on eggshells is not a precarious undertaking. It requires no skill or dexterity. You don’t have to be careful. You can jump up and down on eggshells. It will not upset, offend or harm you or anyone else. They will crunch under your feet. There is no caution required. They will stick to your shoe, so try not to track them in the house.

Walking on eggs, however, is an entirely different undertaking, and, to my knowledge, is nearly impossible. A great deal of caution should be employed before attempting to put the full weight of your body on an egg. The result will be extremely messy and also a waste of food. I will be offended and upset if you deliberately track this mess on my rug.

Ergo, the meaning of the idiom “walking on eggs”: treading carefully in a situation that might offend, upset or harm someone.

Do we say, “I need to go to the store and get some eggshells”? or “I think I’ll fry me up a mess of eggshells”? No, we do not. There is no usage where we substitute the word eggshell for egg except mangling this one simple idiom.

Next you’ll be telling me you’re chomping at the bit, so nip it in the butt.