This is by no means a complete Ghost Hunting dictionary. These are just the terms that came to mind, and I hope to add to the list as others occur, or are suggested.
Anomaly-(Webster's) deviation from the common rule :
IRREGULARITY;
something anomalous
: something different, abnormal, peculiar, or not easily classified
When something unusual or unexpected is captured on film or video, that is an example of an anomaly.
Apparition-a ghostly figure
Banshee- A Celtic (Irish or Scottish) form of unpleasant ghost or spirit
Channeling- when a medium allows a spirit or entity to use him or her as a means of communication
Cold Spot- many paranormal investigators that the unexplained presence of cold spots may indicate the presence of a ghost or spirit. The theory is that spirits need to use energy to attempt to manifest, and that they draw that energy from the surrouding atmosphere.
Dowsing Rods- some researchers believe that dowsing rods can help indicate spirit energy, although this is controversial. Dowsing rods are rods or sticks used for hundreds of years to find water underground or lost objects; the rods are supposed to cross when in the presence of the water, object, or spirit energy.
Edtoplasm- Ectoplasm is a solid, liquid, or vaparous substance which some researchers believe is sometimes produced by ghosts or spirits. It often shows up in photographs as a mist or blob.
Electronic Voice Phenomena- voices that appear on tape or video that should not be there; for instance, when there was no one in the room or in a foreign language, or a female voice when there are no females present. Some of the least easily explained phenomena, especially since the voices often seem to be responding to an investigator or a situation.
Electronic Magnetic Fields- electronic and magnetic fields are important to ghost hunters because it is believed that spirit energy can cause major fluctuations in these fields.
EMF meters/detectors- handheld devices which measure changes in the electronic and magnetic fields
Empathy- (Webster's) -the action of understanding, being aware of, being sensitive to, and vicariously experiencing the feelings, thoughts, and experience of another of either the past or present without having the feelings, thoughts, and experience fully communicated in an objectively explicit manner; also : the capacity for this . People with this ability are sometimes called "empaths" and may pick up feelings from buildings or objects, even if those buildings and objects are not haunted.
Energy- Quantum Physics tells us that everything is made of energy. Ghosts and spirits may be energy that no longer occupies a body. If so, that energy may be felt and it may be measurable.
Entity-(Webster's)-something that has separate and distinct existence and
objective or conceptual reality
Fear- the most common reaction to the unknown and unexplainable. Ghost hunters may feel fear, but in order to be good investigators that need to feel stronger curiosity, and to be able to control their fear.
Ghost- generally considered to be the manifestation of a person or an animal who is no longer living. Ghosts seem to sometimes be interactive and intelligent, and to sometimes be merely endlessly replaying one event, rather like a hologram.
Haunting- a continuous manifestation of unexplained phenomena, whether it is visual, auditory, through smells, or by the moving of objects. Any unexplained visitation associated with ghosts or spirits.
Haunted location- a place associated with the presence of ghosts or other unexplained phenomena
Ley lines- ley lines are hypothetical lines connecting geographical areas that may be centers of powerful earth energy.
Manners- knowing how to behave in relationship to other people, living or dead. Not knowing the nature of an entity or spirit is no excuse for rudeness.
Metaphysics- the study of that which seems to go beyond the law of physics
Orbs- orbs are very controversial, because in photos and on video so many things can appear to be orbs. Orbs are little balls of light or energy, and many people think that they may be signs of spirit energy or that a spirit is trying to manifest or make itself known. However, dust, bugs, and many other things may appear very impressive on film, and therefore orbs must be treated with caution as evidence.
Ouija Board- board used to attempt to communicate with disembodied spirits or ghosts. Many researchers consider these boards to be dangerous and unethical, but others feel they are useful tools. My personal feeling is that they should be used, if ever, only with the greatest cautio and respect.
Paranormal- beyond normal experience; seeming to defy the known laws of science.
Parapsychology-the scientific study of paranormal phenomena.
Poltergeist- literally, "noisy ghost," usually associated with locations where objects are being moved or people are being shoved, etc. Often seems to be centered on individuals in severe stress, and often may not be the result of ghosts or haunting, except in cases where no people are present when things are moved.
Psychic- a person who obtains, or appears to obtain, knowledge in a paranormal manner, as in seeing the future or the past, or having unexplainable knowledge
Respect- what we owe to the dead, whether in spirit form or not. Also, what any researcher should show to the owner of the property being inspected and the property itself.
Spirit- in these circumstances, another word for ghost, sometimes considered a less negative term
Wraith- an apparition which often appears just before or just after a death