Fancy jargon and complexity
Science is loaded with jargon which serves as an efficient way to get a complex idea across in a neat package. Scientists name everything and give precise definitions. Thus, jargon is a hallmark of science.
Whereas the jargon of science is meant to be precise and useful, the jargon of pseudoscience is additionally used to convey an impression of technicality, and may deliberately be used to obfuscate the outsider. Inventive jargon and elaborate detail can hide the lack of real discussion about evidence and logical argument. 
Pseudoscientific gurus frequently misapply genuine scientific words. New scientific-sounding terms are created because they also sound right to an untrained ear. The most egregious offense may be the misuse of scientific concepts that are typically peppered throughout their literature and commentary. “Energy” and “quantum” are perhaps the most commonly incorrectly applied and highly overused terms.
While it sounds impressive, fancy-sounding language does not make a concept scientific. Elaborate systems of painstaking analysis and exacting interpretation doesn’t make what comes out at the other end any more true. It’s just a sham.
When a proponent asserts absolute certainty in their interpretation, and will not provide a reasonable answer to “What evidence would make your theory false?” (or worse, requires the scientist to “Prove me wrong”) it is a clear signal of pseudoscience. Intellectual honesty would require one to admit that any theory may eventually someday be proven false but can never be proven absolutely true.
 Levitt, N. (1999). Prometheus Bedeviled, Rutgers Univ Press. p. 90