The name Lannah is a relatively modern coinage, with its origins likely rooted in the Semitic languages of the Middle East. It bears a resemblance to the Hebrew name Leah, which means "weary" or "tired." However, Lannah itself does not appear to have a direct translation or meaning in Hebrew or other ancient languages.

One of the earliest recorded instances of the name Lannah can be found in the 19th century novel "The Millionaire Baby" by Anna Katharine Green, published in 1905. In the novel, Lannah is the name of a character, though little is known about the author's inspiration for the name.

Throughout the 20th century, Lannah remained an uncommon name, but a few notable individuals bore it. Lannah Bailey Bunton (1892-1984) was an American politician who served as a Democratic member of the Texas House of Representatives from 1931 to 1935. Lannah E. Sawers-Pearce (1935-2019) was a Canadian artist and educator known for her abstract paintings and printmaking.

More recently, Lannah Dunn (born 1988) is a British actress best known for her role in the television series "The Royals." Lannah Lane (born 1970) is an American singer-songwriter and musician who has released several albums and toured with various bands.

While the name Lannah may not have a long and storied history, its unique sound and spelling have contributed to its growing popularity in recent decades. It has been embraced by parents seeking a distinctive name for their daughters, often drawn to its melodic quality and potential meanings associated with words like "lanah," meaning "tender" or "delicate" in various languages.