Where does “piolhinho” come from?

piolhinho (Portuguese) comes from Portuguese piolho, from Old Portuguese peollo, from Late Latin peduclus, from Latin peduculus, from Latin pedīculus, from Latin pēdis, from Latin pēs, from Ancient Greek μέτρον — Derives agent nouns from verbs, denoting someone...

Ancestry of “piolhinho”, step by step

Step	Language	Word	Meaning
1	Portuguese	piolho	louse
2	Old Portuguese	peollo	louse
3	Late Latin	peduclus	Alternative form of pēduculus
4	Latin	peduculus	Alternative form of pēdiculus; louse
5	Latin	pedīculus	A little foot
6	Latin	pēdis	louse
7	Latin	pēs	a foot, in its senses as
8	Ancient Greek	μέτρον	something used to measure: measure, rule, weight;...
9	Ancient Greek	-τρον	Forms instrument nouns
10	Proto-Hellenic	-tron	Forms instrument nouns from verb stems
11	Proto-Indo-European	-trom	Forms nouns denoting a tool or instrument
12	Proto-Indo-European	-tḗr	Derives agent nouns from verbs, denoting someone...

Every word from Proto-Indo-European -tḗr →Every word from Ancient Greek -τρον →Every word from Ancient Greek μέτρον →