Denshi Jisho — Online Japanese dictionary

硬い かたい 1: hard; solid; tough;
2: stiff; tight; wooden; unpolished (e.g. writing);
3: strong; firm (not viscous or easily moved);
4: safe; steady; honest; steadfast;
5: obstinate; stubborn;
6: bookish; formal; stuffy
Common word, Adjective 
硬い石 かたいいし hard stone
Noun 
硬い文章 かたいぶんしょう stiff style
Noun 
硬い表情 かたいひょうじょう stiff expression
Noun 
硬いことは言いっこなし かたいことはいいっこなし let's put formalities aside; let's not speak so stiffly
Expression 

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