A great-grandfather of one's spouse.

(geology) The continuous system of rift valleys in the East African Rift.

plural of great white hope

A highly skilled white/Caucasian challenger for leadership in a field whose top ranks are dominated by non-Caucasians; especially a field which was once dominated by white Caucasians, and is now dominated by those of black-African descent.

The official nickname for the state of Michigan in the United States of America.

Acrocephalus arundinaceus, an Old World warbler.

(economics) A chart plotting the relationship between inequality and intergenerational social immobility in several countries around the world.

(anatomy) A large vein running from the apex of the heart to the base of the ventricles.

Death balances all.

(geometry) a segment of a great circle