Grave was the word that was used to describe mass before the word "kilogram" was introduced.
(Grave; was; the word that was used to describe mass) (the word; was used; to describe mass before the word "kilogram" was introduced) (the word; was introduced; )
Grave the word the word
was was used was introduced
the word that was used to describe mass
to describe mass before the word "kilogram" was introduced