serrate, cerate

Serrate or serrate describes something with notched edges, or a coin with grooved edges--
This serrate leaf comes from a different species of tree.
When this coin was new it had a serrate edge.

Cerate or cerate ( rhymes with serrate ) means a mixture of wax, fat, or oil and medicinal ingredients--
A cerate can be applied to cloth, which can be used to cover a burn or wound.
The doctor prescribed a cerate, because it will stay on the skin better than an ointment.

Now that you know that, you can say--
"The edge is serrate or jagged; apply this cerate to gauze and cover the wound with it."