Definitions for flummox Informal.
to bewilder; confound; confuse.
There are things you do that you later learn to regret,that flummox you, unimaginable things that make youpause and reconsider who you really are, what you arecapable of.
Flummox arose in the early 1800s; its origin isunknown.
Source: flummox – Word of the Day | Dictionary.com