Having a great extent; covering a large area; vast. / (figuratively) Considerable in amount. / Serving to extend or lengthen; characterized by extension.

In an extensive manner, widely. / To a great extent.

The degree or property of being extensive.

plural of extensiveness

(obsolete) extent; expanse

(obsolete) Outreaching; expansive; extended, superficially or otherwise.

The quality of being extensible.

(uncountable) The condition of being extensive / (countable) The extent to which something is extensive

(uncountable) The state of being extensive or of having extension / (countable) The degree to which something is extensive

The act of extending; a stretching out; enlargement in length, breadth, or time; an increase / The state of being extended