Isseis is a 6 letter English word. It's valid Scrabble word worth 5 points. It's valid Words with friends word worth 5 points.
You can make 23 anagrams from letters in isseis (eiisss).
1935-40; Japanese, equivalent to is first + sei generation (earlier it-sei, it-seĩ Middle Chinese, equivalent to Chinese yì one + shēng birth)