A fathom is a way to measure water depth. One fathom equals six feet or about two meters. People use it in boats and oceans.
The lake is twenty fathoms deep.
Boats stay clear where it is five fathoms.
To fathom means to understand something fully. This is often about difficult or strange ideas. It means thinking carefully to find the meaning.
I can’t fathom his strange idea.
She tried to fathom the hard problem.
To fathom water means to measure how deep it is. People do this by dropping a weighted line or rope into water. It helps sailors know if the water is safe.
The sailor fathomed the sea depth with a line.
He fathomed the river to find shallow places.
This meaning is about finding the cause or reason for something hard to understand. It often shows it is a mystery or surprising.
No one could fathom why she left home.
They tried to fathom the cause of the noise.
This use shows a deep or total understanding of something, often feelings or ideas. It is often used in negative sentences to say that someone does not understand something.
I can’t fathom his true feelings.
You cannot fathom how tired I am.
