alum

verb

(transitive) To steep in, or otherwise impregnate with, a solution of alum; to treat with alum.

She decided to alum the fabric before dyeing it.

意味（1）

(transitive) To steep in, or otherwise impregnate with, a solution of alum; to treat with alum.

The silk should be boiled at the rate of 20 parts of soap per cent. , and then alumed. The aluming need not be so strong as for the fine crimson