look up any word, like b4nny:
 
1.
Definition one:

A recently discovered medical condition affecting the tissue surroundings and meniscus of the human knee. Characterized by malformation and scarring of patellar tissue, sydknee usually requires localized corrective surgery, given that causation is often had by way of prior untreated athletic injuries or genetic deficiencies that can lead to a polio-like paralysis if left untreated.

"Sydknee" is a compoundment of the words "syd" and "knee", with the former term having its roots in digital typefaces. The condition is exceptionally rare, and has generated the vast majority of its notoriety due to a comical (albeit short) article found within a 2009 edition of the "Annals of Internal Medicine". The author, a doctor of osteopathic medicine, poked fun at the unconventional name unsuited for placement within a naming system comprised mostly of Latin, Arabic, and archaic terms.

Definition two:

"Sydknee" is also an alternative spelling of the female name "Sydney". While not one of the most popular names for newborn girls in America, it has been increasing in prevalence and presence, given its usage in a popular and disturbing indie song about underage sex occurring between two siblings.

Why people would choose to name their child after the drug-addicted, whorish, and mentally disturbed character portrayed in the song, I don't know.
Definition one:

After having been injured at a recent soccer game and complaining to her physician about patellar joint pain, unusual patterns of contusion, and general malaise, Wilma's doctor performed a computerized axial scan of the area and diagnosed her with sydknee.

Definition two:

John decided to name his daughter "Sydknee".
by HeinrichVonHinterland June 20, 2011