herb

From Middle English herbe/erbe, from Old French erbe, from Latin herba. The initial H was restored in spelling in the 15th century to match the Latin root, even though nobody was actually saying it.

For hundreds of years after that spelling fix, the H stayed silent in pronunciation — only catching up with the written form in the 19th century, and even now many speakers still don't say it.

It's a doublet of yerba, meaning the two words descend from the same root but arrived in English by different paths.