What does accelerate mean?
The definition of accelerate
Ac*cel”er*ate, v. t.
[imp. & p. p. Accelerated; p. pr. & vb. n.Accelerating.]
Etym: [L. acceleratus, p. p. of accelerare; ad + celerare to hasten; celer quick. See Celerity.]

1 To cause to move faster; to quicken the motion of; to add to the speed of; — opposed to retard.
2 To quicken the natural or ordinary progression or process of; as, to accelerate the growth of a plant, the increase of wealth, etc.
3 To hasten, as the occurence of an event; as, to accelerate our departure. Accelerated motion (Mech.), motion with a continually increasing velocity.

— Accelerating force, the force which causes accelerated motion. Nichol.
— To hasten; expedite; quicken; dispatch; forward; advance; further.