Definition of jumbos:
(adj) :
Especially large or powerful.
(n) :
An especially large or powerful person, animal, or thing.
(n) :
(India, Kenya) An elephant.
(n) :
(British English) A large airplane, such as those used for intercontinental travel.
(n) :
(Western Pennsylvania) Synonym of bologna (“type of meat”).
(n) :
(engineering) A platform-mounted machine for drilling rock.