noun🔗Share要塞, 砦A secure or fortified place; a stronghold, a fortress."The castle served as the king's fastness during the long siege. "その城は、長い包囲戦の間、王の砦として機能した。militaryarchitecturebuildingChat with AIVocabulary GamePractice Reading
noun🔗Share速さ, 迅速さThe state of being fast."The fastness of the internet connection is crucial for online learning. "インターネット接続の速さは、オンライン学習に不可欠です。qualitybeingChat with AIVocabulary GamePractice Reading
noun🔗Share堅牢度The ability of a dye to withstand fading."The fabric's fastness ensured the colorful school banners would stay vibrant for years. "生地の堅牢度により、カラフルな学校のバナーは何年も鮮やかな状態を保ちました。colormaterialtechnicalindustryqualityChat with AIVocabulary GamePractice Reading
