(n.) a highly venomous snake
The etymology of cobra turned up on HH today, and it’s an interesting one.
So here’s a little bit more about it.
Despite having a Portuguese name, cobra snakes aren’t native Portugal, of course. Instead, that name probably entered the language via Portugal’s colonies in central Asia—most notably Goa, Calicut, and the other Indian seaports that proved massively important trade centres in the Portuguese Empire. The name cobra—Portuguese for “serpent”—in turn has its roots in Latin, and comes from colubra, a Latin word for a female snake. (No one is entirely sure where that Latin word has its roots, but one not-too-outlandish theory suggests it might be related to colus, the Latin word for a spinner’s distaff.)
The Portuguese name, cobra, was used at expense of the cobra’s local Indian name, nāga—a term, derived from the Sanskrit word for “serpent,” that remains in use in Hindu and Jainist mythology to refer to a legendary race of half-human, half-snake beings. (And it’s also, we can presume, the likely inspiration for the name of Nagini in JK Rowling’s Harry Potter stories.)