Any girl extremely obsessed with any celebrity, t.v. show, movie, book, or other entertainment/media who is participating in fan actitivities such as message boards, fanfiction
, or conventions.
Has been used in the past as derogatory but has become less and less in certain fandoms. Fan girling frequently happens with large amounts of squee
The noun would be fangirl
or occasionally fengirl
, though the later is usually used as plural.
Her whole message board was fan girling over the new episode.