Abarim Publications' online Biblical Hebrew Dictionary
The root ליש (lysh) isn't used as a verb in the Bible but it is assumed to be the root of the masculine noun ליש (layish), meaning lion. A comparable root occur in Arabic, where it means to be strong. It is, however, not certain whether this verb was derived from a companion noun meaning lion or vice versa. In the Bible the noun ליש (layish), meaning lion, occurs only in Job 4:11, Proverbs 30:30 and Isaiah 30:5. A much more common Biblical word for lion is ארי (ary).