We found one dictionary that defines the word be made of sterner/tougher stuff:

General (1 matching dictionary)

1. be made of sterner/tougher stuff: Merriam-Webster

▸ Words similar to be made of sterner/tougher stuff ▸ Usage examples for be made of sterner/tougher stuff ▸ Idioms related to be made of sterner/tougher stuff ▸ Wikipedia articles (New!) ▸ Words that often appear near be made of sterner/tougher stuff ▸ Rhymes of be made of sterner/tougher stuff ▸ Invented words related to be made of sterner/tougher stuff