(inorganic chemistry) The sum of calcium and magnesium ion concentrations in water, normally expressed in mmol/L

plural of total hardness

(derogatory) Alternative spelling of tryhard

Alternative form of hard-and-fast

(idiomatic, of rules, etc) strictly maintained

guided by practical experience and observation rather than by theory / (idiomatic) hardheaded, stubborn / (of a person) tough and relentlessly practical and thus not given to sentiment.

A printed copy of a digital document, as opposed to a copy in electronic form.

(idiomatic) Having difficulty hearing; somewhat deaf.

(computing) To build absolute and unchangeable values into a program such that they can only be changed by modifying the source code.

(vulgar, slang) Tough, uncompromising and inflexible.