noun, used as a suffix
Suffix attached to place names to indicate a flat area or plateau. Not used as a standalone noun.
秋田平は、秋田県にある平野の一部です。
Akita-daira is part of a plain in Akita Prefecture.
上高地は、梓川沿いの美しい平です。
Kamikōchi is a beautiful plateau along the Azusa River.
台地 is a standalone noun for 'plateau' or 'tableland', whereas 平 is a suffix used in specific place names.
The reading だいら is a native Japanese word (yamato-kotoba) meaning 'flat area'. The kanji 平 is used for its meaning 'flat' or 'level'.