1. A line connecting points on the earth's surface having the same mean summer temperature

Derived forms: isotheres

• for the moment
• for the most part
• for the record
• for the time being
• forage
• forager
• foraging
• foram
• foramen
• foramen magnum
• foramen of Monro
• foraminifer
• Foraminifera
• foraminous
• forasmuch as
• foray
• foray into
• forayer
• forbear
• forbearance
• forbearing
• forbid
• forbiddance
• forbidden
• Forbidden City