Where does “parasitismo” come from?

parasitismo (Portuguese) comes from Portuguese parasita, from Latin parasītus, from Ancient Greek παράσιτος, from Ancient Greek παρά, from Latin verēdus, from Gaulish werēdos, from Proto-Celtic *uɸoreidos — horse.

parasitismo (Portuguese): parasitism interaction in which one organism benefits at the expense of another without killing them

Definitions

parasitism interaction in which one organism benefits at the expense of another without killing them

Ancestry of “parasitismo”, step by step

Step	Language	Word	Meaning
1	Portuguese	parasita	parasite
2	Latin	parasītus	guest
3	Ancient Greek	παράσιτος	one who eats at the table of another, parasite;...
4	Ancient Greek	παρά
5	Latin	verēdus	A fast or light breed of horse; courier's horse; hunter
6	Gaulish	werēdos	horse
7	Proto-Celtic	*uɸoreidos	horse

Every word from Proto-Celtic *uɸoreidos →Every word from Gaulish werēdos →Every word from Latin verēdus →