fathom
Definition
To understand the meaning of something, especially something difficult; also, a unit of length equal to six feet, used in measuring depth of water.
Español Entender el significado de algo, especialmente algo difícil; también, una unidad de longitud igual a seis pies, utilizada para medir la profundidad del agua.
Example
"I can't fathom why she would say such a thing."