What is another word for rock hard?
Pronunciation: [ɹˈɒk hˈɑːd] (IPA) 
Rock hard is a descriptive phrase often used to describe something that is solid, unyielding, and unbreakable. There are several synonyms for this phrase, including the phrases 'adamantine,' 'impregnable,' and 'indestructible.' 'Adamantine' refers to something that is as hard as diamonds; it is most commonly used to describe materials or substances that are incredibly strong and difficult to break. Meanwhile, 'impregnable' describes something that cannot be entered or penetrated, while 'indestructible' refers to something that is impossible to destroy or damage. Other synonyms for rock hard include 'rock-solid,' 'firm as a rock,' and 'unbending.' All these terms can be used interchangeably to describe something that is strong, sturdy, or unbreakable.
