The main point of learning Latin, or so our Latin teacher used to tell us, was to be able to spot the origin of English words and thence guess their meaning.
Now, gastrocnemius is a Greek word at root; but, working on the same principle, what does it mean?
Well, as you probably already know, the gastro- bit means stomach; and as it happens the -cnemius bit means leg.
So. A stomach-leg. Or possibly a leg-stomach.
If you have, then you probably have a career as a science-fiction writer.
If not, then you can blame the Ancient Greeks. I mean, what did the Ancient Greeks ever do for us?
Well, apart from democracy, the alarm clock, the Olympics, juries, geometry...
Word To Use Today: gastrocnemius. The gastrocnemius muscle is in the calf, and is used especially for running and jumping.
The word comes from the Greek words gastēr, stomach, and knēmē, which means leg. The idea is that the calf of the leg bulges like a well-filled stomach.
Mind you, as the speaker of a language which calls this part of the anatomy by a word meaning young cow, I'm really in no position to throw stones.