Where does “lachryma Christi” come from?

lachryma Christi (Renaissance Latin) comes from Latin lachryma, from Old Latin dacrima, from Proto-Italic *d(r)(k)akrunā, from Proto-Indo-European dáḱru-, from Proto-Indo-European dr̥ḱ-h₂eḱru- — eye bitter.

Ancestry of “lachryma Christi”, step by step

StepLanguageWordMeaning
1LatinlachrymaAlternative spelling of lacrima
2Old Latindacrimatear
3Proto-Italic*d(r)(k)akrunā
4Proto-Indo-Europeandáḱru-tears; tear
5Proto-Indo-Europeandr̥ḱ-h₂eḱru-eye bitter
Every word from Proto-Indo-European dr̥ḱ-h₂eḱru-Every word from Proto-Indo-European dáḱru-Every word from Proto-Italic *d(r)(k)akrunā