Halloween

UK: /hæləʊˈiːn/

US: /ˌhæləˈwin, ˌhɑl-/

US: (hal′ə wēn′, -ō ēn′, hol′-)

WordReference Random House Learner's Dictionary of American English © 2025

Hal•low•een or Hal•low•e'en /ˌhæləˈwin, ˌhɑl-/   n. [uncountable* countable]

1. Religion the evening of Oct. 31;
   the eve of All Saints' Day, observed esp. by children, who dress in costume and play trick or treat.

WordReference Random House Unabridged Dictionary of American English © 2025

Hal•low•een  (hal′ə wēn′, -ō ēn′, hol′-), n. 

1. Religion the evening of October 31;
   the eve of All Saints' Day;
   Allhallows Eve: observed esp. by children in costumes who solicit treats, often by threatening minor pranks.

Also, Hal′low•e'en′. 

• (All)hallow(s) + e(v)en² 1550–60

Collins Concise English Dictionary © HarperCollins Publishers::

Halloween, Hallowe'en / ˌhæləʊˈiːn/ noun

1. the eve of All Saints' Day celebrated on Oct 31 by masquerading; Allhallows Eve

Etymology: 18th Century: see Allhallows, even²