toughen What is the Definition of toughen?Verb:make tough or tougher Other meanings of toughen (synonyms, cognates). ENRU toughen закалять Frequently viewed: definition of buckettough definitionunusual in a sentencedefinition of watchtennis definitionwrite meaningforget meaningforth meaningdefinition of encounterworld meaningcurrently in a sentenceteam definition 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