render something down
1. Lit. to cook the fat out of something. Polly rendered the chicken fat down to a bit of golden grease that she would use in cooking a special dish. Jane rendered down the fat for use later. The cook rendered it down.
2. Fig. to reduce or simplify something to its essentials. Let's render this problem down to the considerations that are important to us. Can't we render down this matter into its essentials? Not all of this is important. Let's render it down.
render something in(to) something
to translate something into something. Now, see if you can render this passage in French. Are you able to render this into German?
render something to someone or something
and render something up (to someone or something)to give something to someone or a group. You must render your taxes to the government. I will render my money to the tax collector. I had to render up all my earnings.