window box

1. 1.

   a long narrow box for growing plants on a windowsill

   Broaderbox

Questions about window box

What does window box mean?

window box means "a long narrow box for growing plants on a windowsill".

Is window box a common word?

window box is banded "Rare" — specialist or archaic — most readers will not have met it. The band comes from how often the word appears in a large corpus of everyday English, not from an editor's impression.