mystify
verb (used with object)
to perplex, puzzle, or baffle; defy the understanding of.
Used to describe an action that began in the past, has continued continuously, and is still in progress.
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Though the gaucho thinks he has at last got the clue to what has been mystifying them, like all skilled tacticians he intends for a time keeping it to himself.
From Gaspar the Gaucho A Story of the Gran Chaco by F.C. Tilney