Of timber; having fibers that run in parallel(adjective)
WordNet. Princeton University. 2010.
Use "straight-grained" in a sentence
"* WOOD: Standard wood such as straight-grained, strong walnut runs $1,500."
"The split ash logs I was burning were clean, white and straight-grained, so I took one outside next day and took my axe to it, splitting off a triangular piece roughly the right size for a handle."
"Squinting against the morning sun across the flat calm Solent, we made out the silhouettes of dozens of yachts off Cowes: a distant forest of masts and sails that not long ago would have been wooden, crafted from straight-grained spruce, but were probably almost all aluminium or carbon fibre."