The word “Aphrodite” was used as a password by Horace Slughorn to enter his office during the 1996-1997 school year. The password was spoken to a portrait of a fleet of sailing ships, causing it to swing aside and reveal a hidden entrance. The only known use of this password occurred after the burial of the Acromantula, Aragog. Harry Potter, under the influence of Felix Felicis, accompanied a drunk and sentimental Horace Slughorn back to his office from Rubeus Hagrid's hut. Slughorn spoke the password to the portrait, allowing them both to enter. It was during this subsequent conversation that Harry successfully persuaded Slughorn to give him the true memory concerning Tom Riddle's questions about Horcruxes.
Aphrodite is the name of the ancient Greek goddess of love, beauty, pleasure, and procreation. Her Roman equivalent is the goddess Venus. The choice of this password is characteristic of Horace Slughorn's personality, reflecting his appreciation for the finer things in life, including luxury, pleasure, and beauty. The classical and somewhat flamboyant nature of the name aligns with Slughorn's tastes and extravagant lifestyle.
In the film adaptation of Harry Potter and the Half-Blood Prince, this password and the secret portrait entrance to Horace Slughorn's office are not featured. After Aragog's burial, Slughorn and Harry Potter are shown returning directly to his office through a conventional door (film).