careless vs undesigned

careless

adj
  • Not giving sufficient attention or thought, especially concerning the avoidance of harm or mistakes. 

  • Not concerned or worried (about). 

undesigned

adj
  • Not designed, not intended. 

  • Not designed, not drawn or planned before being made. 

How often have the words careless and undesigned occurred in a corpus of books? (source: Google Ngram Viewer )