Any of the eight annual Wiccan festivals. They mark the changing of the seasons, celebrate traditional harvests, and are days to worship and give thanks.
Samhain is one of the 8 pagan Sabbats and falls on October 31st.
Samhain marks the third and final harvest of the year, and is a time to remember the dead. You might decorate your altar with pumpkins, leaves or small gourds. Celebrate with divination, carve a jack-o-lantern or place an offering of food and drink in the window for passing spirits!
A form of divination, by peering into something. Typically, a crystal ball is used, but you can also scry with a mirror, bowl of water or even a candle flame.
Skyclad means to be naked, specifically during ritual. Some believe that clothing interferes with the natural energies of magick, and that it brings you closer to the Earth. There are many reasons why a Wiccan might choose to go skyclad, but it is up to you. Some covens work this way, and you may not want to join one if it is not comfortable for you.
To use the smoke from burning herbs or incense to cleanse negative energy. It's a Native American term, and white sage or sweetgrass are typically used. A bundle of these herbs is called a 'smudge stick'.
So Mote it Be
It translates to "Let it be so" or "So shall it be", and is often used as part of the dialog during rituals, typically in closing. The actual origins of the phrasing is a little obscure and based in old Anglo-Saxon.
A spell is a ritual that has a particular purpose. Some rituals are purely celebratory, but a spell is done to accomplish something. Spells might be used for healing, prosperity, attracting a mate, or even to rid yourself of bad habits.
The Summerlands is the place where your spirit goes after you die, before your next reincarnation. Here your spirit (or soul) rests between lifetimes and reflects on the things learned. You may be reunited with friends and loved ones here before your next life begins. Not all Pagans believe in this version of the afterlife, and there are many variations.
Syncretism is the blending of beliefs from one or more religions.