Halloween

or Hal·low·e'en

[ hal-uh-ween, -oh-een, hol- ]
/ ˌhæl əˈwin, -oʊˈin, ˌhɒl- /

noun

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

Origin of Halloween

First recorded in 1550–60; (All)hallow(s) + e(v)en2

British Dictionary definitions for hallowe'en

Halloween

Hallowe'en

/ (ˌhæləʊˈiːn) /

noun

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

Word Origin for Halloween

C18: see Allhallows, even ²