Where does “leilac” come from?

leilac (Welsh) comes from English laylock, from Old French lilac, from Arabic لِيلَك, from Persian نیلک, from Persian نیل, from Arabic نيل, from Middle Persian 𐭭𐭩𐭫, from Sanskrit नील — to lead.

Ancestry of “leilac”, step by step

StepLanguageWordMeaning
1Englishlaylock
2Old Frenchlilac
3Arabicلِيلَكlilac
4Persianنیلک
5Persianنیلindigo
6Arabicنيلverbal noun of نَالَ; indigo; to colour indigo
7Middle Persian𐭭𐭩𐭫indigo
8Sanskritनीलof a dark color
9Proto-Indo-EuropeanneyH-to lead
Every word from Proto-Indo-European neyH-Every word from Sanskrit नीलEvery word from Middle Persian 𐭭𐭩𐭫