An odd word, render.
I suppose the commonest sort of render is to show or give in a formal, often official, way. Accounts are rendered for examination, for instance, and we are asked to render to Caesar those things which are Caesar's.
On the other hand, sometimes the giving is anything but formal - as when someone renders someone unconscious with a great knock on the head - so perhaps the link is the intensity of the intention. You see this in passion had rendered him insane, for instance.
The idea of deliberate intention leads us to the artistic sort of rendering, where someone might, despite all attempts at dissuasion, give a rousing rendering of We All Live In A Yellow Submarine, or, if a visual artist, the play of light on a rose bush. From here we are led to the sort of rendering which translates one language into another, or a novel into a film, or, lowering the tone, rather, which turns fat into oil by melting it.
There are other rarer meanings of render to do with ropes on boats and three-dimensional computer images, but the meaning which really puzzles me is the rendering you see on walls.
Rendering involves covering a wall with a coat of plaster or cement, but what's that got to do with giving or presenting something? If anything, this sort of rendering involves covering something up.
Hmm...well, perhaps if we've covering something up then we're back to where we started: with the accounts.
Thing To Do Today: render something. This word comes from the Old French rendre from the Latin reddere to give back.