Where does “leituga” come from?

leituga (Old Portuguese) comes from Latin lactūca, from Latin lác, from Proto-Indo-European ǵlákts — milk.

Ancestry of “leituga”, step by step

Step	Language	Word	Meaning
1	Latin	lactūca	—
2	Latin	lác	—
3	Proto-Indo-European	ǵlákts	milk

leituga — Etymology, Origin & Word History | Etymology Explorer