"To define the characteristics" means to describe or explain the features, qualities, or attributes that define or distinguish something or someone. Full definition
Genre - mixing and examination of process became defining characteristics of the next half - century's art. (pacegallery.com)
To put it in computer - age terms, it's a film in a binary universe, all about singular contradiction as defining characteristics rather than a spectrum of detail. (seanax.com)
This film's most defining characteristic is the stellar acting across the board. (screenanarchy.com)