What is the suffix for drainage?

There isn't a single, universally accepted suffix specifically for "drainage." However, there are several suffixes used in words related to drainage, depending on the specific context:

Suffixes relating to the action of draining:

* -age: This suffix indicates an action or process, and is commonly used to form nouns. Examples: "drainage," "leakage," "passage," "storage."

* -ing: This suffix can also indicate an ongoing action or process. Example: "draining"

Suffixes relating to the result of draining:

* -ed: This suffix indicates something that has been drained. Example: "drained"

* -able: This suffix indicates something that can be drained. Example: "drainable"

Other suffixes:

* -ator: This suffix refers to a person or thing that performs an action, so "drainator" could be used to describe a device that drains. However, this is not a common word.

* -er: This suffix can also refer to something that performs an action, so "drainer" is a common word referring to a device that drains.

Ultimately, the best suffix to use depends on the specific meaning you want to convey.