Where does “raríssimo” come from?

raríssimo (Portuguese) comes from Portuguese -íssimo, from Latin -issimus, from Proto-Italic *-isəmos — forms superlative forms of adjectives.

Ancestry of “raríssimo”, step by step

StepLanguageWordMeaning
1Portuguese-íssimoforms the absolute superlative
2Latin-issimusadded to an adjective noun to form its...
3Proto-Italic*-isəmosforms superlative forms of adjectives
Every word from Proto-Italic *-isəmos →Every word from Latin -issimus →Every word from Portuguese -íssimo →