Pteron

When I was reading the Wikipedia of fly, I learned that flies are classified as diptera, which means “the two-winged flies” or “an order of insects having one pair of membranous wings”. The ptera part comes from the Ancient Greek πτερόν (pterón) meaning “feather” or “wing”.

There are two good examples in English that come from the same origin: pteranodon and helicopter. The former is the combination of pter- and anodon, meaning “without teeth” (instead, they had a crest). The latter has the prefix helico- that means “spiral” (cf. English helix).

The word πτερόν (pterón) comes from the PIE *pétr̥ meaning “feather” or “wing”, whence we have the English word feather.