lo

Etymology 1

From Middle English lo, loo, from Old English lā (“exclamation of surprise, grief, or joy”). Conflated in Middle English with lo! (interjection), a corruption of lok!, loke! (“look!”) (as in lo we! (look we!)). Cognate with Scots lo, lu (“lo”). See also look.

intj

1. (archaic) look, see, behold (in an imperative sense).
   Caliban: Lo, lo again! Bite him to death, I prithee. c. 1610-11, William Shakespeare, The Tempest, act III, scene ii
   Awake! for Morning in the Bowl of Night, Has flung the Stone that puts the Stars to Flight: And Lo! the Hunter of the East has caught 1859, Edward Fitzgerald, The Rubáiyát of Omar Khayyám: The Astronomer-Poet of Persia, page 1
   …, Lo, these many years do I serve thee, …. first published 1611, reprinted c. 1900, The Bible, King James version, Luke 15:29
   Emperor Ling went in state to the Hall of Virtue. As he drew near the throne, a rushing whirlwind arose in the corner of the hall and, lo! from the roof beams floated down a monstrous black serpent that coiled itself up on the very seat of majesty. The Emperor fell in a swoon. 1925, Charles Henry Brewitt-Taylor, Romance of the Three Kingdoms, translation of original by Luo Guanzhong
   "Tambi will be here in..." He computed carefully. "... in exactly twenty seconds." And, lo, Tambi appeared at that very moment. 1959, Anthony Burgess, Beds in the East (The Malayan Trilogy), published 1972, page 588

Etymology 2

Variant of low.

adj

1. Informal spelling of low.