Wiktionary
n. The conical, nipple-like projection of the petrous part of the temporal bone, that is situated behind the ear in humans and many other vertebrates, and serves as a site of muscle attachment.
WordNet
n. process of the temporal bone behind the ear at the base of the skull [syn: mastoid, mastoid bone, mastoidal]
Wikipedia
The mastoid process is a conical prominence projecting from the undersurface of the mastoid part of the temporal bone. It is located just behind the ear canal, and lateral to the styloid process.
Usage examples of "mastoid process".
Hazleton was speaking into his throat mikes, audible only to the receiver imbedded in Amalfi's right mastoid process.
Her mind-comm unit was far more efficient than the standard TGO model and was embedded in the mastoid process behind her left ear.
His face had an unnaturally ruddy cast where vacuum had burst capillaries beneath the skin, and until his eardrums healed he was hearing by a little bone-conduction unit taped to the mastoid process beside his left ear, but on the whole he didn't look too bad for what he'd survived.
Rod had a microphone implanted in his upper jaw, just above his front teeth, and an earphone behind his ear, in his mastoid process.
Her breath vibrated in her mastoid process, made sharp rasping sounds in her Comnet ear link.
When they first took us on board, they installed a little broadcaster of the sleep-waves, surgically, right next to our skulls - under the right mastoid process.