seatagen.

/ˈsiːtɪdʒ/Etymology: < seat v. + -age suffix.
the world > space > [noun] > sufficient space or room > for sitting > on seats or benches
1889 19 July 2/2 More than half the total seatage.
This entry has not yet been fully updated (first published 1911; most recently modified version published online March 2018).