(vulgar, slang) Tough, uncompromising and inflexible.

(vulgar, slang) A tough and combative person.

(chemistry) Water with a high concentration of dissolved minerals, especially calcium, making it difficult to lather with soap.

(US) An alcopop resembling lemonade.

(computing) A device used for storing large amounts of data for a computer that persist while the computer is turned off.

(of a boiled egg) Cooked to a solid consistency. / (of a person, especially a detective) Callous and unsentimental.

simple past tense and past participle of hard-boil

(bodybuilding) A person who has difficulty gaining weight through either diet or exercise.

A thin horizontal bony plate of the skull, located in the roof of the mouth.

(phonetics) The "c" sound pronounced /k/, as in "cat" and "cabin", as distinct from the soft c, pronounced /s/, in "cent", "center" and "circuit".