razor, enchanted
A razor that is very thorough, but has to be told very clearly what the
user wants.
Harry was given one for his seventeenth birthday by Bill and Fleur; Fleur's father then cautioned him, saying that otherwise Harry might have less hair than he'd like (DH7).
Remembrall
A glass ball the size of a large marble. In its default state
(when nobody is touching it), a Remembrall is full of white smoke.
When picked up and held in a person's hand, a Remembrall will glow scarlet
if there's something the person has forgotten to do.
The name "Remembrall" = "remember all", and also
suggests the object's ball shape.
Neville's Gran sent him a Remembrall by owl post during his first term at Hogwarts; Draco's theft of this as a practical joke led directly to Harry being selected as Seeker for the Gryffindor House team (PS9).
Remembralls are banned from the examination hall at Hogwarts (OP31).
Resurrection Stone
See RESURRECTION STONE.
Revealer
"Eraser"-like object that makes invisible ink visible.

