Thurisaz (Proto-Germanic): the strong one, giant; Thiuth (gothic): the good one; Thorn (Old English): thorn; Thurs (Old Norse): giant
Phonetic value: voiceless th as in "thorn."
Esoteric interpretation of name: Asa-Thór, the enemy of unfriendly forces.
Ideographic interpretation: the hammer, or the thorn on a branch.
Thurisaz is the directed cosmic force of destruction and defense. It's the archetypal instinctual will, without self-consciousness. This Rune is a symbol of thunder and lightning and is equal to Mjöllnir, Thor's hammer. This is the weapon that destroys etins and protects Midgard and Asgard. Thor is similar to the giants (thursar) in his size and brute strength, and is therefore an ideal counterforce to them. The Æsir always strive to maintain their enclosures in the multiverse, and the power of this Rune is essential to this effort. The idea expressed by this aspect is the same as that of the hammer sign. This is the forward-thrusting force that destroys powers that are hostile towards cosmic order. These hostile powers are not morally "evil" they are merely detrimental to the established and instinctual life urge that is represented by the Æsir and Vanir and expressed by humanity.
Thurisaz holds the life-death polarity. It is the ultimate power to assimilate potential energy of two extremes of kinetic energy into a pattern of action. Thurisaz is a projectable form of applied power. Generally, this may work as a limitation and direction of a variety of energy-form binary pairs found throughout the Rune row. That is, any Rune that is essentially energetic may be combined with any Rune that has primarily paradigmatic characteristics by the force of Thurisaz and directed in a real way.
This is also a Rune of regeneration and fertilization. As the lightning announces the crop-bringing rains, so Thurisaz breaks down barriers and fertilizes so that new beginnings may be made. The thorn is the thorn of awakening that dispels the power of the svefnthorn (sleep-thorn).
A quickening of your development is indicated here. Yet even in times of accelerated growth, you will have reason to halt along the way, to reconsider the old, to integrate the new. Take advantage of these halts.
If you are undergoing difficulties, remember: The nature of your passage depends upon the quality of your attitude, the clarity of your intention and the steadfastness of you will. Be certain that you are not suffering over your suffering.
Drawing Thurisaz Reversed demands contemplation on your part. Hasty decisions at this time may cause regrets, for the probability is that you will act from weakness, deceive yourself about your motives, and create new problems more severe than those you are attempting to resolve. Impulses must be tempered by thought for correct procedure. Do not attempt to go beyond where you haven't yet begun. Be still, collect yourself, and wait on the Will of Heaven.
--Copied word for word from The Book of Runes by Ralph H. Blum