| pseudoscience |
a theory, methodology, or the like, such as astrology, that claims an unjustified scientific basis or application. |
| pshaw |
an expression of disbelief, annoyance, or the like. |
| psi1 |
abbreviation of "pounds per square inch." |
| psi2 |
the name of the twenty-third letter of the Greek alphabet. [2 definitions] |
| psilocybin |
a solid, crystalline hallucinogenic obtained from a certain type of mushroom. |
| psi particle |
an unstable meson that is thought to be composed of a quark and its antiparticle. |
| psittacosis |
a viral infection of birds that can be transmitted to humans as an illness similar to pneumonia. |
| psoriasis |
a chronic disease of the skin that causes dry, scaly patches. |
| psst |
used to attract the attention. |
| PST |
abbreviation of "Pacific Standard Time," the standard time used in the Pacific Coast region of the United States, eight hours behind Greenwich time. |
| psych |
(informal) to intimidate with psychological pressure; make uneasy or nervous (usu. fol. by "out"). [3 definitions] |
| psyche |
the human soul or spirit. [3 definitions] |
| psychedelic |
of, relating to, or producing heightened or distorted sensory perceptions, hallucinations, and sometimes extreme behavioral patterns. [3 definitions] |
| psychiatrist |
a doctor who specializes in treating mental and emotional disorders. |
| psychiatry |
the medical science or practice of diagnosing, treating, and preventing mental and emotional disorders. |
| psychic |
of, caused by, or pertaining to nonphysical, spiritual, or supernatural processes or influences. [4 definitions] |
| psycho |
(slang) a psychopath. [2 definitions] |
| psycho- |
mind. [2 definitions] |
| psychoactive |
of a chemical agent or drug, affecting or capable of affecting the mind or mental functions. |
| psychoanalysis |
a method of studying and treating mental disorders and illnesses by analyzing dreams, early childhood memories, and other experiences as keys to the subconscious mind. |
| psychoanalyst |
one who specializes in the study and techniques of psychoanalysis. |