beforenoon

From before +‎ noon. Probably modelled after afternoon.

beforenoon (uncountable)

1. (rare, nonstandard) Forenoon.
   • 1738, William Andrews, Remarkable News from the Stars: Or, an Ephemeris for the Year 1738 […] , London: A. Wilde, for the Company of Stationers, page unnumbered:

     […] But if the month and day be on the right hand, as July 26, then they South at 6 h. 14 min. in the Morning, or Beforenoon, contrary to the ſignification of the Letters, A. for afternoon, and B. for beforenoon; and ſo of the reſt.

   • 2019, VK Bhamare, RD Dhembare, KV Deshmukh, AS Ingale, RU Desai, “Population dynamics of Chrysodeixis acuta (Walker) and Gesonia gemma (Swinhoe) infesting sunflower intercropped with pigeonpea and its correlation with weather parameters”, in Journal of Entomology and Zoology Studies, volume 7, number 5, →ISSN, page 942:

     During the course of investigation the weather parameters viz., minimum temperature, maximum temperature, beforenoon relative humidity, afternoon relative humidity, rainfall and number of rainy days were varied from 11.6 °C to 22.8 °C, 27.9 °C to 31.7 °C, 73 to 100 per cent, 29 to 82 per cent, 0.00 to 184.0 mm and 0 to 4 days, respectively.