A "Thrall" is love work or a "love spell" placed on a specific person in order to make that individual love the spell caster, or whom the spell caster is working for.
The term thrall comes from the word "enthrall," which means to enslave, to ensnare, to captivate, or to bewitch.
Though referred to as love spells, thralls actually are believed to work by creating an overwhelming obsession in the target or else produce a zombie-like state in the target. Thralls do not produce true love, as the magic invoked violates the targeted person's free will. Because of such, thralls are considered by some to be a form of black magic. For this reason members of the Wiccan faith do not perform love spells on specific people due to the karmic consequences, but rather only cast love spells to meet someone new, someone who is also seeking new love.
A good example of a thrall can be found in the 1996 movie, The Craft. The character of Sarah places a thrall on the character of Chris, a boy she has a crush on. The spell evokes in Chris a dangerous obsession for Sarah, an obsession that ultimately backfires on Sarah, resulting in an attempted rape.
It is possible this scenario in the movie was taken from real-life stories told of people who suffered consequences from performing thralls. Even I have heard a story of a New Orleans witch who performed a thrall on a man only to find herself become a genuine rape victim. These stories of consequences in performing thralls are usually told as a means of communicating morality and ethics in the use of magic. They are the witches' version of morality plays and serve to express the ultimate warning for dabblers of the magical arts, "BE CAREFUL OF WHAT YOU WISH FOR, BECAUSE YOU JUST MIGHT GET IT."
Perhaps my most favorite portrayal of the consequences of performing a thrall can be seen in the episode of Buffy The Vampire Slayer The Series, titled "Bewitched, Bothered and Bewildered". In the episode, the character of Xander gets a witch to perform a love spell on a specific girl. Hilarious consequences ensue.
NOTE: In hoodoo/rootwork/conjure we will perform works to get people to love them. If the person being worked on has a spark of desire for the person then there usually aren't any problems. Problems tend to arise when a person wants to force someone to love them when they don't even know that person exists. Also, depending on the person's will, it may take a lot of effort and time to subdue the person being worked on. I would caution workers to treat everything on a case-by-case situation.
For further examples of thralls, click on the links below. Perform these at your own risk.
Love Me Spiritual Supplies In Hoodoo/Rootwork
A GRAVEYARD DIRT LOVE SPELL FOR ATTRACTION (Scroll Down)
Specific Love Spells
"LOVE ME OR DIE": A JACK BALL TO GOOFER A MAN FOR LOVE
A 3-CANDLE LOVE SPELL TO ATTRACT LOVE, ROMANCE, AND PASSION
A LODESTONE AND RED CANDLE LOVE SPELL TO ATTRACT NEW LOVE
The following non-thrall spell can be used on a specific person to find out how much they love you. It was recorded by Cat Yronwode, owner of the LuckyMojo Curio Co. The spell is called, "All My Love Come To Me".
All My Love Come To Me