Where does “picuț” come from?

picuț (Romanian) comes from Romanian pic, from Vulgar Latin picca, from Latin pittus, from Proto-Celtic bikkos, from Proto-Indo-European bʰég-ko-s, from Proto-Indo-European -kos — Creates deadjectival and desubstantival...

Ancestry of “picuț”, step by step

Step	Language	Word	Meaning
1	Romanian	pic	a drop; a bit
2	Vulgar Latin	picca	—
3	Latin	pittus	small, little
4	Proto-Celtic	bikkos	small, little
5	Proto-Indo-European	bʰég-ko-s	—
6	Proto-Indo-European	-kos	Creates deadjectival and desubstantival...

Every word from Proto-Indo-European -kos →Every word from Proto-Indo-European bʰég-ko-s →Every word from Proto-Celtic bikkos →