ad ‧ he ‧ sion /ədˈhiːʒ ə n/ BrE AmE noun
[ Date: 1400-1500 ; Language: Latin ; Origin: adhaesio , from adhaerere ; ⇨ ↑ adhere ]
1 . [uncountable] when something sticks to something else
2 . [countable] medical a piece of ↑ tissue (=skin) that grows around a cut or diseased area