Keress bármilyen szót, mint például: kappa
 
1.
A vowel combination consisting of a weak vowel and a strong one.

It is more commonly used as an insult, seeing as it is a legitimately funny word.
There is a diphthong in "loud."

YOU'RE A DIPHTHONG.
Beküldő: Doyman. 2007. október 7.
 
2.
A small article of clothing worn by a homosexual man under a swimsuit or alone. Especially used at nighttime.
When I went swimming with Peter, he was wearing the sexiest diphthong.
Beküldő: Eptomologizzle 2005. március 10.