Last seen in:
- L.A. Times Daily - Nov 12 2025
- Universal - Oct 29 2023
- Canadiana - Nov 2 2020
- Canadiana - Jul 23 2018
- L.A. Times Daily - May 14 2017
- The Washington Post - May 14 2017
- New York Times - Oct 24 2015
- Eugene Sheffer - King Feature Syndicate - Jul 19 2014
- New York Times - Jul 7 2013
- New York Times - Jun 26 2013
Related Clues:
- Heat and then cool
- Toughen, as to hardship
- Become hardened (to)
- Get used to (Var.)
- Harden: Var.
- Make immune
- Cause to become hardened to
- Make accustomed (to)
- Accustom (var.)
- Temper, toughen
- Fire or glaze as in kiln
- Heat and cool slowly in order to toughen
- Heat and cool to temper or toughen
- Toughen by heating and slow cooling
- Toughen by a process of gradually heating and cooling