Where does “senectud” come from?

senectud (Spanish) comes from Latin senectūs, from Latin -tus, from Proto-Italic -tus, from Proto-Indo-European -tus — Derives action nouns from verb roots.

senectud (Spanish): old age

Definitions

old age

Ancestry of “senectud”, step by step

Step	Language	Word	Meaning
1	Latin	senectūs	aged, very old
2	Latin	-tus	Forms the past participle of verbs; Forms...
3	Proto-Italic	-tus	—
4	Proto-Indo-European	-tus	Derives action nouns from verb roots

Every word from Proto-Indo-European -tus →Every word from Latin -tus →Every word from Latin senectūs →