[1] : The Collaborative International Dictionary of English v.0.48

gain \gain\, v. i.
   to have or receive advantage or profit; to acquire gain; to
   grow rich; to advance in interest, health, or happiness; to
   make progress; as, the sick man gains daily.
   1913 webster

         thou hast greedily gained of thy neighbors by
         extortion.                               --ezek. xxii.
                                                  12.
   1913 webster

   gaining twist, in rifled firearms, a twist of the grooves,
      which increases regularly from the breech to the muzzle.

   to gain on or to gain upon.
   a to encroach on; as, the ocean gains on the land.
   b to obtain influence with.
   c to win ground upon; to move faster than, as in a race or
       contest.
   d to get the better of; to have the advantage of.
       1913 webster

             the english have not only gained upon the venetians
             in the levant, but have their cloth in venice
             itself.                              --addison.
       1913 webster

             my good behavior had so far gained on the emperor,
             that i began to conceive hopes of liberty. --swift.
       1913 webster
see also:
gaining twist to gain on to gain upon 

Gain >> G Words
Gain, definition of term: Gain
gain_pag1.html

Capital Gain >> C Words
Capital Gain, definition of term: Capital Gain
capital+gain_pag1.html

Call Upon >> C Words
Call Upon, definition of term: Call Upon
call+upon_pag1.html

Bear Upon >> B Words
Bear Upon, definition of term: Bear Upon
bear+upon_pag1.html

Agreed Upon >> A Words
Agreed Upon, definition of term: Agreed Upon
agreed+upon_pag1.html