Admission, aka an admission fee was a fee paid which granter one access to a location.

It was customary for Ferengi to pay admission fees in order to visit someone inside their home. In 2371, Brunt did so when visiting Quark and Rom's family home on Ferenginar.(DS9: "Family Business")

In 2372, planning his own funeral, Quark decided to charge two slips of latinum per person to hear his eulogy, which was to be held in the holosuite. When Rom expressed uncertainty about doing so, Quark upped it to three. (DS9: "Body Parts")

In 2377, annoyed with Doctor Lewis Zimmerman's holographic pets, Leonard, a talking iguana, and Roy, a fly used for surveillance, The Doctor described Jupiter Station to Reginald Barclay as a three ring circus and suggested they charge admission. (VOY: "Life Line")