passthrough

noun6

1. •
   The act or process of passing through.
2. •
   As of a signal through a device or network.
3. •
   As of increased costs through a business entity to its customers through increased prices.

   • The airlines called the fuel surcharge a passthrough, but did not rescind it until well after fuel prices had returned to previous levels.
4. •
   Allowing the use of some resource unchanged from one system to another.
5. •
   A legal entity intended to not incur (income) taxation at the entity, but solely at the beneficiaries.

   • Partnerships, limited-liability companies, and Subchapter S corporations are the main US passthroughs.
6. •
   A wall opening intended to allow something to be passed through it.