n. A safe, comical way to announce one's absolute bewilderment.
Ken paints all the new cars in his household to resemble an early US Naval Squadron, the 3rd Observation Squadron, for instance. He just likes the bright color schemes…

Bill travelling down the interstate sees the newly painted-up cars travelling in a row, all with the ancient naval markings, and remarks, "What the fadoo is going on here?"

Tiger has recently had slew of affairs, although he has a remarkably beautiful wife. Now, he could be facing a costly divorce, loss of product endorsements, diminished public favour, etc.

Jo Anne, reflecting on Tiger's looming plight remarks, " What the fadoo was he thinking?"

Fadoo is a word that replaces the harsher, sexually charged taboo word f***.
by Never Was An Arrow II December 8, 2009
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A penis. Usually used when deacribing a simple drawing of a penis and two balls.
Someone drew a fadoo in the bathroom stall and it looks like a goofy looking penis
by Hoobeeboo November 17, 2017
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