As an adjective bulky
is being large in size, mass, or volume.
As a noun bulkiness is
the characteristic of being bulky, or of having bulk.
bulky
English
Adjective
(er)
Being large in size, mass, or volume.
Unwieldy
(bodybuilding) Having excess body mass, especially muscle.
bulkiness
English
Noun
(-)
The characteristic of being bulky, or of having bulk.