In the Book of Mormon, Laman and Lemuel are the two eldest sons of Lehi and the older brothers of Nephi. According to the text, they lived around 600 BC. They were notable for their rebellion against Lehi and Nephi, becoming the primary antagonists of the First and Second Books of Nephi. They and their descendants became known as the Lamanites, while the descendants of Nephi and their other brothers became the Nephites.
Laman was Lehi's first-born son. He rejected the teachings of his father (in particular Lehi's prophecy of the forthcoming destruction of Jerusalem in 600 BC. He and Lemuel persecuted and beat their brothers Sam and Nephi, who supported Lehi. Because God chose Nephi to lead Lehi's descendants after his death, Laman maintained that he had been robbed of his birthright, resulting in constant wars between the two peoples for nearly 600 years.
Most famously, Lehi tried to influence his son towards a more righteous attitude by naming a river in Arabia after him, and uttering a didactic couplet:
"Oh that thou mayest be like this river, Continually running towards the fountain of all righteousness!"
Unfortunately, the river Laman was most probably a seasonal wadi, containing water only during the brief rainy season, being nothing but a dry riverbed most of the year. Being like the river named after him meant that Laman was very inconstant.
Laman, along with his brothers, returned to Jerusalem to obtain the Brass Plates.
In the Maya language, "laman" means "herdsman." The Lamanites of The Book of Mormon are shown as a largely pastoral people, with the raising of flocks as a main economic activity.