I don't know how many other meanings 'octopus' may have, but to a scuba diver, octopus also means the backup regulator that we use to provide breathing gas to an out-of-air buddy.
The origin lies in the looks of a regulator setup with its many hoses, and adding the backup regulator made it look even more like a cephalopod.
I'm a bit annoyed that 'octopus' was later used only to refer to the one backup regulator, a rather one-armed species, rather than to the entire setup of different elements, looking much more like the source of its name. Well, such is life.

Life is a beach, and then you dive.

Life is a beach, and then you dive.