̷ ̷ˈ ̷ ̷ ̷ ̷ˌfī(ə)r, -īə noun
( -s )
Etymology: acidify + -er
: one that acidifies: as
a. : a chemical element or group whose presence produces acidity — orig. used of oxygen
b. : a substance (as sulfur or aluminum sulfate) used to increase soil acidity