gain on vs outgallop

gain on

verb
  • To win ground upon; to move faster than, as in a race or contest. 

  • To encroach on. 

  • To obtain influence with. 

  • To get the better of; to have the advantage of. 

outgallop

verb
  • To run faster than; to outdistance. 

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