geek out
verb
geeked out;
geeking out;
geeks out
Definition of geek out
informal
: to behave like a geek
especially
: to become excited or enthusiastic about a favored subject or activity
Rail buffs get to geek out aboard a 1924 Pullman-Standard Victorian Coach or a 1952 Granite Eagle, the latter a three-level dining car with a glass observation dome on the upper deck and a sunken lounge on the lower level. — The Wall Street Journal … fans will really geek out over the reproduced notepad that features Henson's original outlines and story ideas. Not that I did or anything. — Dalton Ross