viv ‧ i ‧ sec ‧ tion /ˌvɪvəˈsekʃ ə n, ˌvɪvɪˈsekʃ ə n/ BrE AmE noun [uncountable]
[ Date: 1700-1800 ; Language: Latin ; Origin: vivus 'alive' + English section 'cutting' ]
the practice of doing medical or scientific tests on live animals
—vivisectionist noun [countable]