Oo-mox

Oo-mox is the act of rubbing or massaging a Ferengi's ears. 

Such is the importance of oo-mox to Ferengi males, the two-hundred and twenty-third Rule of Acquistion states "Beware the man who doesn't take time for oo-mox". (, SS DS9 (... Loved I Not Honor More))

There was also a book, The Ferengi Guide to Sexual Fulfillment: The Joys of Oo-moxing, released on the subject. 

Another book was Oo-mox for Fun and Profit. 

One of the chapters of Doctor Posk of the Ferengi Wellness Institute's guide Guarding Your Investment: Keeping Your Children Profitable dealt with excessive compulsive oo-moxing in Ferengi males aged one to eighteen. 

After Ishka learned that Quark was oo-moxing when he was young, she put numbing ointment on his ears. 

Rom would often perform oo-mox on his own ears.