n. & v. archaic
n. 1 a festive occasion; a drinking-bout. 2 a kind of liquor drunk on such an occasion.
v.intr. make merry; celebrate with drinking etc. wassail-bowl (or -cup) a bowl or cup from which healths were drunk, esp. on Christmas Eve and Twelfth Night. wassailer n.
[ ME ws hil etc. f. ON ves heill, corresp. to OE wes hal 'be in health', a form of salutation: cf. HALE(1) ]