/θruː/
Through has 12 different meanings across 3 categories:
A large slab of stone laid in a dry-stone wall from one side to the other; a perpend.
"The ancient tomb was sealed by a massive granite through that covered the entrance completely."
A coffin, sarcophagus or tomb of stone; a large slab of stone laid on a tomb.
In plain English: Through is not really used as a noun, so it usually means going from one side to another without stopping.
"He ran his finger through his hair to calm himself down before the interview."
having finished or arrived at completion
"certain to make history before he's done"
"it's a done deed"
"after the treatment, the patient is through except for follow-up"
"almost through with his studies"
(of a route or journey etc.) continuing without requiring stops or changes
"a through street"
"a through bus"
"through traffic"
Passing from one side of something to the other.
"The hiker climbed over the ridge and walked through the dense forest on the other side."
In plain English: Through means going all the way from one side to the other without stopping on the journey.
"The clear glass cup let me see through to the bottom where the ice cubes were floating."
throughout the entire extent
"got soaked through in the rain"
"I'm frozen through"
"a letter shot through with the writer's personality"
"knew him through and through"
"boards rotten through and through"
From one side to the other by way of the interior.
"The bullet passed through the window and shattered the vase on the floor."
In plain English: Through means going all the way from one side to the other without stopping on the surface.
"She fell through while ice skating on the frozen pond."
From one side of an opening to the other.
"The bullet flew straight through the window and hit the wall on the other side."
The word "through" comes from Old English þurh and traces back to Proto-Germanic roots meaning "to pass through." It entered Middle English with a slight spelling variation before settling into its modern form.