two-piece vs twofold

two-piece

adj
  • comprising two pieces 

noun
  • A garment consisting of two separate parts; especially such a swimsuit 

twofold

adj
  • Having two parts, especially two different parts. 

  • Double; duplicate; multiplied by two. 

adv
  • In a double degree; doubly. 

How often have the words two-piece and twofold occurred in a corpus of books? (source: Google Ngram Viewer )