- slang an erection of the penis
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Examples from the Web for stiffy
At the door Stiffy said, as a matter of form: "Coming, Mahooley?"
Of them all only Stiffy, in his little compartment at the back, was busy.
When he was not adding up his columns, Stiffy was for ever taking stock.
Stiffy came quickly out of his little box to see what was up.
Stiffy and Mahooley fired their cook and went with the rest.