雷らい鈷こMeanings1nounground stone tool from the late Jomon periodArchaeological term for a specific type of stone implement; compare with 独鈷石 (どっこいし).See also: 独鈷石この遺い跡せきからは、縄じょう文もん時じ代だい晩ばん期きの雷らい鈷こが出しゅつ土どした。A ground stone tool from the late Jomon period was excavated from this site.