Seeker - Searches for the Snitch and tries to catch it before the other team to end and often win the game. See 'Quidditch'

Shrinking Solution - AKA Shrinking Potion. Causes the drinker to shrink to a younger form. If brewed correctly it is bright green, if brewed incorrectly it can be poisonous. 

Sickle - Silver coloured wizarding currency. There are 29 Knuts to a sickle and 17 Sickles to a Galleon. 

Slytherin - One of the houses at Hogwarts, founded by Salazar Slytherin. Students traditionally show such traits as cunning, resourcefulness and ambition. The emblem is a snake, the house colours are green and silver, and the house ghost is the Bloody Baron.

Snake Fangs - When crushed, are used as an ingredient in potions such as Strength Potion, Boil-Cure Potion and Wideye Potion. It must not be harvested from venomous snakes.

Snitch - Small, golden, winged ball. When caught ends the game and earns 150 points for the team. See 'Quidditch'

Snufflifors - Snufflifors. Wand movement: a short, sharp whiplash movement above the head. A Class-A Transfigurative Spell. Transfigures books into mice. The caster gains temporary control over the mouse and can instruct it carry out one order. Does not create real life due to Gamp's Law of Elemental Transfiguration.

Softening Charm - Spongify. Wand movement: an S-shape and then point at the object. Softens hard objects (metals, stones and living things are not conductive), making the object rubbery and bouncy. Useful for protection.

Solar System - Eight planets and many moons, asteroids, comets and meteoroids. The sun holds the solar system together with its gravity, and the planets rotate around the Sun in orbit (an elliptical shape). The Inner Solar System and Outer Solar System are separated by the Asteroid Belt (made of 7000 asteroids) between Mars and Jupiter.

Solution - A type of potion which is a homogeneous mixture (composed of one phase) where a salute has been dissolved in a solvent. It takes on the characteristics of the solvent, including the phase.

Sorting Hat - A brown, ragged looking hat which is used to put first year Hogwarts students into houses. It originally belonged to Godric Gryffindor and was enchanted by the four founders with brains and some personality so it could continue to sort the students when the four had passed on. Before sorting the students, the hat sings a song to introduce itself and the four houses. Although the hat looks into the minds of the students to determine their house, it also takes their choices into consideration.

Strength Potion - A yellow potion which increases the drinker's strength. May be related to Strengthening Solution.

Strengthening Solution - A potion which presumably increases the drinker's strength. Brewed in two stages and requires several days to mature in between. May be related to Strength Potion.

Stinging Nettle - See 'Nettle'

Swedish Short-Snout - Silvery blue dragon which lives in the northern mountains of Sweden. It breathes a blue flame which is extremely hot and they are agile flyers. See 'Dragon'

Swelling Solution - A potion which causes enlargement on contact. The potion does not need to be drank, it can just be touched for the effects to take place.