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]
(..) Nobody move. Tell me that's not what I think it is. Muscovite. Muscovite. What's muscovite? - Muscovite is a thin type of rock formation. - How thin? Well, so thin that the slightest change in weight and pressure... ...can cause it to shatter. And we're standing on a lot of it. (..)2008 Journey to the Center of the Earth