to lean (against) (against the lean of a chair or against the wall)
to open a crack (For leaving doors open just a tiny bit.)
The core idea of this root was:
leaning, to be at an incline
This sense is still pretty obvious in words like to lean, to incline or to recline, but also clinic or client come from that root. The origin of these is an old Greek word with the simple sense of “laying in bed sick”.
Here’s an (incomplete) list of English relatives: