oc ‧ to ‧ pus /ˈɒktəpəs $ ˈɑːk-/ BrE AmE noun ( plural octopuses or octopi /-paɪ/) [countable]
[ Date: 1700-1800 ; Language: Modern Latin ; Origin: Greek oktopous 'scorpion' , from okto 'eight' + pous 'foot' ]
a sea creature with eight ↑ tentacle s (=arms)