the soft reddish wood of either of two species of sequoia trees
"The carpenter selected a redwood beam because its soft, reddish grain was ideal for interior paneling."
The species Sequoia sempervirens.
"The towering redwood in the foggy valley belongs to the species Sequoia sempervirens, distinct from its inland cousin."
In plain English: A redwood is an extremely tall type of tree found on the west coast of North America that has reddish-brown bark and can grow to be hundreds of feet high.
"The giant redwoods in California are so tall that people need ladders to see their very tops."
A surname.
"Many people in the valley share the redwood surname, a legacy from their ancestors who planted trees there."
The word combines the English words red and wood, directly describing the reddish-brown color of the tree's bark. It entered common usage to distinguish these large trees from other varieties based on that distinctive hue.