toughen What is the Definition of toughen?Verb:make tough or tougher Other meanings of toughen (synonyms, cognates). ENRU toughen закалять Frequently viewed: respond meaningcollect meaningtolerate meaningconsent meaningbinary meaningwhereas meaninghot meaningraiser in a sentencemessage meaningtalking meaningmajor in a sentenceteach meaning A B C D E F G H I J K L M N O P Q R S T U V W X Y Z