Where does “Seniang” come from?

Seniang (Tagalog) comes from Tagalog -ing, from Spanish -ín, from Latin -īnus, from Proto-Italic -īnos, from Proto-Indo-European -iHnos, from Proto-Indo-European -no- — adjectival suffix.

Ancestry of “Seniang”, step by step

Step	Language	Word	Meaning
1	Tagalog	-ing	Used to form diminutives
2	Spanish	-ín	chico + -ito → chiquito + API → chiquitín
3	Latin	-īnus	of or pertaining to; -ine
4	Proto-Italic	-īnos	of/belonging to
5	Proto-Indo-European	-iHnos	Creates adjectives of materials
6	Proto-Indo-European	-no-	adjectival suffix

Every word from Proto-Indo-European -no- →Every word from Latin -īnus →Every word from Proto-Italic -īnos →