quintibling

Five siblings who are close enough that they can almost be considered quintuplets.

Man, Stephen sure loves being a quintibling. He and his four brothers always seem to hang out together.

quintibling by Mizelle Avery August 20, 2017

quintaling 

a person that owns all tests with little effort

congradulations you got top of the class for quintaling that math test

quintaling by ttillo October 1, 2011

quintilingual

someone who speaks 5 languages

someone who can speak multiple languages
more specifically 5
therefore
quintilingual

quintilingual by Zaara December 30, 2007