slang Smoking or being intoxicated by smoking crystal meth (methamphetamine hydrochloride). A reference to the ice-like appearance of the drug.
Skaters generally refer to their skateboards simply as their boards. No point in getting fancy. Sometimes you hear the word "deck," but that refers specifically to the wood plank part of the skateboard. Calling a skateboard "wood" or "ride" pegs someone as a novice trying too hard to sound like a skater.
Merlin was born sometime during the medieval era. It is possible that he was taught by Salazar Slytherin himself, given the time period Merlin lived in.
Moses came way before Jesus, and lived to a much older age. Moses was estimated to be born around 1400 years before Jesus. If you are asking how long they lived, Moses lived to be around 120 years, Jesus 33 years. “And Moses was 120 years old when he died.” —Deuteronomy 34:7.