Edit: With the feedback I got and the new info in the comments to the Question showing this to now be the right train of thought, I'm no longer going to try to make this work.
This is a partial answer
and a work in progress. I think I have the final answer and am working backwards from there.
A is a friend and foe of the wind:
airplane; it works with and against the wind, and it also fits the first 4 letters of my guess for the answer.
Without B, wheels will go astray:
The letters from my final answer guess are: rieme, so I'm guessing something about a rim, but I still don't have a good enough guess on this.
C bears around it what all others of its kind conceal:
sad words? They describe what other words try to avoid saying? Going off the "adows" of my proposed final answer.
What was once thick and green:
prairie meadows; we've cut down most of the prairies to make way for cities, roads, and fields. What's left of the prairies are for grazing animals, so they aren't very thick anymore.
The sections are:
prai rieme adows