What does hardening mean in crosswords?

hardening means: the act of making something harder (firmer or tighter or more compact)

Which crossword clues can have hardening as the answer?

Possible clues for hardening include "Makes firmer".

Word entry · 9 letters

Best crossword clue

"Makes firmer"

9 letters · collected on this word page

9 lettersPart of speech nounSorted adeghinnrStarts with HEnds with G1 cluesCommon crossword word

1H2A3R4D5E6N7I8N9G

01“Makes firmer”9 letters

Not quite right?

H________