Word
lunatic
Phoneticslu·natic
US/ˈɫunəˌtɪk/
UK/lˈuːnətˌɪk/
Definitions
01a reckless person
n. someone who behaves in a very silly, dangerous, or crazy way.
n. a person who acts in a reckless, irrational, or extremely foolish manner. While originally a clinical term, it is now used as a harsh informal pejorative.
“He was driving like a lunatic and almost caused a serious accident.”
“The CEO was described as a lunatic by former employees who witnessed his increasingly erratic and high-risk decision-making.”
Informal
Usage
Often used in the phrase 'drive like a lunatic' to describe dangerous behavior on the road.
Teaching tip
This word is considered offensive if used to describe someone with actual mental health issues; it is best reserved for describing reckless behavior.
02extremely foolish
adj. very silly, dangerous, or not sensible.
adj. extremely foolish, eccentric, or irrational. Often used to describe ideas, policies, or behaviors that seem to lack any logic.
“It was a lunatic idea to go hiking in the middle of a storm.”
“The critics dismissed the proposal as a lunatic fringe theory that lacked any empirical evidence or logical foundation.”
Informal
Usage
Commonly appears in the fixed expression 'lunatic fringe' to describe extreme or radical groups.
03related to the moon
adj. having to do with the moon.
adj. relating to or influenced by the moon. This sense is the word's original etymological root but is now rarely encountered outside of historical or poetic contexts.
“The old book discussed the lunatic cycles and their effect on the tides.”
“In the poet's vision, the lunatic light of the full moon transformed the familiar landscape into something alien and cold.”
Archaic · Literary
Usage
Almost entirely replaced by 'lunar' in modern scientific and general contexts.
Teaching tip
Learners will likely only see this in 19th-century literature or older texts.
Synonyms
Real-World Examples
“Now, it may forever be the place where an armed, anti-vaccination lunatic showed up at a synagogue where 25 people had gathered to pray.” “One of Alfred’s brothers was confined to a lunatic asylum as a boy and stayed there for life.” Etymology
From Middle English lunatik, from Old French lunatique, from Late Latin lunaticus (“moonstruck”), derived from Latin luna (“moon”), the connection stemming from the belief that changes of the moon caused intermittent insanity.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Word family
Scan code
englishreference.com/q/lunatic