slim jim

noun4

1. •
   (informal) Someone or something very thin.
2. •
   (informal) A thin strip of metal such as spring steel used to unlock automobile doors without a key.
3. •
   A kind of dipole radio antenna.
4. •
   (UK, historical) A narrow necktie worn by teddy boys.

adjective1

1. •
   (informal) Very thin.

   • That ought to make you / An ideal one-girl farm, / And give you a chance to put some strength / On your slim-jim arm. — 1916

noun1

1. •
   (UK) A British Rail Class 33/2 locomotive.