Diminutive of Leonard or Helen; from Germanic 'leon' (lion) + 'hard' (brave), meaning 'brave lion.'
Lennie is a diminutive of Leonard, from the Old High German 'Leonhard' — a compound of 'leo' (lion) and 'hard' (brave, strong, hardy). The name traveled through medieval Europe with enormous momentum: Saint Leonard of Noblac, a sixth-century French hermit who became the patron saint of prisoners and captives, made the name beloved across Christian communities. Leonard was the name of kings, scholars, artists — most famously Leonardo da Vinci, the polymath whose surname simply meant 'from Vinci' but whose first name carried the lion's legacy.
Lennie, the affectionate short form, belongs to a more intimate register. It is a fireside name, a nickname that became a given name in its own right during the late nineteenth and early twentieth centuries when diminutives were fashionable in English-speaking countries. The most indelible literary Lennie is Lennie Small in John Steinbeck's 'Of Mice and Men' (1937) — the gentle giant of prodigious strength and childlike mind whose tragedy gave the name a deep, mournful tenderness in American literary culture.
Steinbeck's Lennie did not diminish the name; he humanized it. Lennie has also been worn by Lennie James, the British actor and playwright known for 'The Walking Dead' and 'Save Me,' and by countless jazz and folk musicians across the twentieth century. It is a name that feels at ease in a diner booth and on a concert stage, that belongs to ordinary people doing extraordinary things. In an era of names stretched to maximum syllabic drama, Lennie's plainspoken warmth feels like a quiet radical act.