Definition of mind-expander in English:

mind-expander

Pronunciation /ˈmʌɪndɪkˌspandə/ /ˈmʌɪndɛkˌspandə/

noun

  • Something that expands or (apparently) extends the capabilities of the mind; specifically a psychedelic drug.

Origin

Late 19th century; earliest use found in Popular Science Monthly. From mind + expander, after mind-expanding.