To faegull is to evacuate your bowels into your own underwear and then use the faecal matter to express your distaste for someone or something by flinging aforementioned faeces at said individual or item at the same
time as making a noise not dissimilar to that of an angry seagull.
This is an
evolution of being seagulled. (see
definition)
The poor stranger wondered what on
earth had happened when the odd man on the
train faegulled him. It was because he was
talking too loudly on his mobile.