Relating to or having a siphon.
The word syphonal is technical and is used in scientific or technical contexts.
Examples:
The syphonal tube helps the fish breathe.
The syphonal system in the aquarium keeps the water clean.
The syphonal structure is important for the functioning of the machine.
The syphonal design makes it easy to move the liquid.
The syphonal mechanism is very useful for draining water.
The syphonal feature is what makes this tool work so well.