The normal time to prune euonymus is in late winter to early spring, so I'd wait and prune it then. If you prune it now, that could cause it to make tender new growth now that will freeze when the weather turns back cold again...next week or whenever it occurs.

Nothing will keep it from growing tall enough to hide the faucet unless you chose an extremely dwarf, mounding variety of euonymus, and this does not look like one of the mounding types. Since you don't remember the name, though, I'm just guessing at that because without a name, we don't know what size is normal for it.

It's a case of bad planting location for an inappropriate plant. Short of killing it now, nothing will prevent it from attaining windowsill size or greater. In a year or two, it will be growing that much each year (windowsill+), even if hacked back.

Thanks! I'm wanting it to be tall, but I want it to also be wide. Why is this a bad location? I planted it to hide the faucet.

Oh, and it's not a dwarf variety. Thanks, Dawn.

Oh, I somehow thought you wanted to NOT hide the faucet...well no worries...yes, you can prune it as said before me.