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]
(..) - Why did your park there? - In case my ex-wife is here. She is not. Her name was not in the credits. - Who does the doctor treat? - Patients. - What is the elbow of my jacket doing? - Wearing thin? Bingo! That was a stretch. - Do you drive this on the weekends? - No, that is my girl's car. (..)1993 Last Action Hero