Source : Webster's Revised Unabridged Dictionary (1913)

Boost \Boost\ (b[=oo]st), v. t. [imp. & p. p. {Boosted}; p. pr.
   & vb. n. {Boosting}.] [Cf. {Boast}, v. i.]
   To lift or push from behind (one who is endeavoring to
   climb); to push up; hence, to assist in overcoming obstacles,
   or in making advancement. [Colloq. U. S.]