approximative vs on the order of

approximative

noun
  • A grammatical construct that expresses approximation. 

adj
  • Of, relating to, or being an estimate or approximation. 

on the order of

prep
  • In the manner of; along the lines of; like; of a similar kind to; more-or-less equivalent to. 

adv
  • Approximately. 

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