Flat lemon is also known as Hirami lemon or Shikwasa. Unlike round lemons, flat lemons are oblate spheroids , like a squished sphere. They're lime-sized with a bumpy, dark green rind that turns bright yellow when ripe. Some people describes the taste being a blend of lemon, lime, and grapefruit.

Examples:

1. I tasted flat lemon juice when I went to Okinawa.
2. My dad squeezed the juice from the flat lemon to add it in the salad.
3. Grandma told me that flat lemon is called Shikwasa in Japan.