passthrough

Short definition from Wiktionary

Noun

1. 1
   The act or process of passing through: As of a signal through a device or network.
2. 2
   The act or process of passing through: As of increased costs through a business entity to its customers through increased prices.
3. 3
   The act or process of passing through: Allowing the use of some resource unchanged from one system to another.
4. 4
   A wall opening intended to allow something to be passed through it.
5. 5
   A legal entity intended to not incur (income) taxation at the entity, but solely at the beneficiaries.