Etymology From Middle English lightful, lihtful (“luminous, providing enlightenment”), from light, liht (noun) + -ful (“full of (a feeling)”, suffix forming adjectives). See more at light (noun).
formlesse eyes doe faile / To see the sun, though brought to lightfull land.a. 1599 (date written), Mary Sidney, “Psalm LVIII”, in The Psalmes of David […], London: From the Chiswick Press by C[harles] Whittingham, for Robert Triphook, […], published 1823, →OCLC, page 101:
His lightfull Lamp reflected on my head, / Whereby I walkt through Darkneſsa. 1619 (date written), [Guillaume de Salluste] Du Bartas, “A Divine and True Tragi-comedy; Iob Triumphant in His Triall: Or The Historie of His Heroicall Patience. In a Measured Metaphrase. The Third Book..”, in Josuah Sylvester, transl., Du Bartas His Deuine Weekes and Workes […], London: […] Robert Young, published 1633, →OCLC, page 470:
1 more example
[The door] had a gloomy and surly aspect, but the hall within was lightful and airy1889, A[rthur] Conan Doyle, Micah Clarke: […], London: Longmans, Green, and Co […], →OCLC, page 164: