Insidious
hardin-SID-ee-us
adjective
Definition
Proceeding in a gradual, subtle way with harmful effects
Examples
“The insidious spread of misinformation undermined public trust.”
“Cancer is an insidious disease that often goes undetected.”
Synonyms
Antonyms
Categories
GRE Tip
Insidious is a hard-difficulty GRE word. On the GRE, you might see it paired with synonyms like "treacherous" or "stealthy" in Sentence Equivalence questions. Look for contrast clues (however, despite, although) that signal the opposite meaning. Words like "overt".
Related GRE Words
surreptitious
Kept secret, especially because it would not be approved of
furtive
Attempting to avoid notice or attention, typically because of guilt or a belief that discovery would lead to trouble
baneful
Causing harm or ruin; pernicious; destructive
deleterious
Causing harm or damage; injurious
pernicious
Having a harmful effect, especially in a gradual or subtle way
vitiate
To spoil or impair the quality or efficiency of; to corrupt
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