A prefix meaning all, or whole.
Sometimes it also means the jioning into a whole.

For example:

panomphaean - all-oracular

panoptic - all-embracing, viewing all aspects

panopticon - prison where all inmates can be watched from one point

panpharmacon - universal remedy

panpsychism - theory that all nature has a psychic side

pansexualism - theory that all thought derived from sexual instinct

pansophy - universal knowledge

pantagamy - universal bachelorhood

pantarchy - government by all the people, world government

pantechnicon - receptacle holding many miscellaneous objects

pantisocracy - government by all equally

pantophagy - omnivorousness

pantophobia - morbid fear of everything

pantopragmatic - meddling in everybody's business

pantoscope - panoramic camera