Originating from Latin roots, the name Lennis is believed to have derived from the Roman family name Lentulus. In ancient times, Lentulus was often used as a cognomen, which referred to the lentil shape of one's ears. Over time, this name has evolved and been adapted in various cultures, leading to its present-day form, Lennis.
The name Lennis experienced fluctuations in popularity over the years, with a peak of 19 births each in both 1946 and 1947. The most recent data point shows a decline to just five births in 2001.