a beam made of wood
"The carpenter carefully measured the timber before cutting it to fit the window frame."
land that is covered with trees and shrubs
"The hikers ventured deep into the timber to find a quiet place away from the road."
Trees in a forest regarded as a source of wood.
"The singer's unique vocal quality, often misspelled as timber when referring to tone color, was captivating the audience."
Misspelling of timbre.
In plain English: Timber is wood that has been cut down from trees and used for building things.
"The workers cut down several trees to gather timber for building the new house."
Usage: Use timber to refer specifically to trees or logs that have been cut down and are ready for processing into lumber, rather than living standing trees which is usually called woodland. This term distinguishes harvested material from the raw state found in an uncut forest.
To fit with timbers.
"The old barn was timbered to reinforce its crumbling walls against the storm."
Used by loggers to warn others that a tree being felled is falling.
"The logger shouted timber as he brought his axe down on the oak trunk."
The word timber comes from Old English timmer, which traces back to a Proto-Indo-European root meaning "build" or "house." It entered Middle English as tymber before becoming the modern term for wood used in construction.