Common (High-frequency) Words of English for GRE

aberrant (adjective): markedly different from an accepted norm When the financial director started screaming and throwing food at his co-workers, the police had to come in to deal with his aberrant behavior.
aberration (noun): a deviation from what is normal or expected Aberrations in climate have become the norm: rarely a week goes by without some meteorological phenomenon making headlines.
abstain (verb): choose not to consume or take part in (particularly something enjoyable) Considered a health nut, Jessica abstained from anything containing sugar–even chocolate.
abstruse (adjective): difficult to understand; incomprehensible Physics textbooks can seem so abstruse to the uninitiated that readers feel as though they are looking at hieroglyphics.
accolade (noun): an award or praise granted as a special honor Jean Paul-Sartre was not a fan of accolades, and as such, he refused to accept the Nobel Prize for Literature in 1964.
acerbic (adjective): harsh in tone Most movie critics are acerbic towards summer blockbusters, often referring to them as garbage.