He plans to 'thin' (out) the young carrots in the garden. [=to remove some of them so that there is more room between the remaining carrots]
His hair is a little 'thin' on top. = He's a little 'thin' on top. [=he does not have a lot of hair on the top of his head]
The bank's decision to raise rates could be 'the thin end of the wedge'. [=many other banks may also decide to raise rates]
(..) l know what ice fishing is ! Sorry. You just seem like, you know, kind of an indoor girl. Anyway, l, uh... l fell through some thin ice. And l'm telling you... ..water that cold, like right down there,... ..it hits you like a thousand knives stabbing you all over. (..)1997 Titanic