That dictionary you quoted isn't necessarily wrong. When you say assistance assumes an actor. The action of the assisted can happen after the assistance enables it, and not necessarily the other way around. Sort of like how Jesus assisted Lazarus to come forth, although he was a rotting corpse.
That is exactly why latter-day saints believe that we are indeed saved by grace. In the end, we truly feel that nothing we can do, on our own merit, is sufficient to save our souls... that only the grace of Christ will empower us to return to live with our Savior again... and Lazarus is a perfect example of that.
I love concept of Charis. It is one of the beautiful lessons in etymology. It is the greek singular for Charities. In my faith we revere the virtue Charity as the pure love of Christ. It is what drove the ultimate act of kindness in him giving his life to redeem man from sin.
So often Latter-day Saints are ridiculed for the teaching that we are saved "by grace, after all we can do." So many of us miss the beauty of that teaching. It leads the ponderer to ask, well then what is it that I can do? The answer... not enough. It leads him to immediately get down on his knees and accept Christ as the redeemer of all men.
I found this on Charis. I have nothing to say with regards to validity of sources, but I identify with what is written here: http://www.bible-researcher.com/grace.html
Truly, I'm sad to see this divide between our faiths. I believe that it is completely artificial. In the end, we as Christians believe that it doesn't matter what we do, how hard we try, how many good works we do, it can never be enough. Only conversion, only a change of heart can qualify us, and only Christ's grace can give us that change of heart. That is what Mormon doctrine teaches. And I don't see why "Orthodox" (though I call them "Reformationist") Christians can't accept that is what LDS doctrine teaches.