eve

Etymology

From a variant of the Middle English noun even (itself from Old English ǣfen), with a pre-1200 loss of the terminal '-n', which was mistaken for an inflection. See also the now archaic or poetic even (“evening”), from the same source.

noun

1. The day or night before, usually used for holidays, such as Christmas Eve.
2. (archaic, poetic) Evening, night.
   I love to see the shaking twig / Dance till the shut of eve Mid-19th century, John Clare, Autumn
   And has she tired of weeping / As she lies down at eve. 1896, A[lfred] E[dward] Housman, chapter XXVII, in A Shropshire Lad, lines 42–43
   Sitting on the dockside at Oban, watching the to-ing and fro-ing in the harbour on a perfect summer's eve, I reflect on a trip which has taken me through our busiest cities to traverse the country's main lines, as well as explore some of the furthest extremities that were literally out on a limb. November 30 2022, Paul Bigland, “Destination Oban: a Sunday in Scotland”, in RAIL, number 971, page 79
3. (figurative) The period of time when something is just about to happen or to be introduced
   the eve of a scientific discovery