Meanings

tangent plane

flushness (esp. of wheels and fenders on an automobile)

same plane

coplanar

hot flush

lunar rover

lunar rover

isobaric surface

façade (building)

spherical harmonics

iron mask (worn by samurai)

young person with a monkey-like face (nickname for Toyotomi Hideyoshi)

ape mask

coupon rate

tangible side of things (such as equipment and facilities; as opposed to the abstract side)

abstract side of things (such as personnel, skill, information; as opposed to physical things)

projected area

advantage

transit of a planet over the solar disk

plane wave