(n.) The fluttering sensation of "butterflies" in one's stomach, increased heart rate, instantly improved mood, and a silly smile.

Gillypitters are most often given and reciprocated in loving and/or budding puppy-dog-eyed relationships, but can also be caused at the interaction or sometimes the mere thought of a particularly strong crush.

Short for ultimate bias. Typically used by fangirls and fanboys to describe their favourite celebrity amongst the many that they are fans of.