a ‧ dapt ‧ er BrE AmE , adaptor /əˈdæptə $ -ər/ noun [countable]
[ Word Family: noun : ↑ adaptability , ↑ adaptation , ↑ adapter , ADAPTOR ; adjective : ↑ adaptable , ↑ adapted ; verb : ↑ adapt ]
an object that you use to connect two different pieces of electrical equipment, or to connect two pieces of equipment to the same power supply