What does the cryptic crossword clue "Chemical that removes hard bit from leather (5)" mean?

The definition is "Chemical". The wordplay uses a deletion. OX (synonym="h") + IDE (synonym="h") = OXIDE; definition: "Chemical" The answer is OXIDE.

Chemical that removes hard bit from leather (5)

Guardian Cryptic #29022 | 3 Down | 2023-03-20 flower