Green’s Dictionary of Slang

maudlin, esp. through drink; thus as n. melancholia.

c.1591		Shakespeare Two Gentlemen of Verona IV ii: Now, my young guest, methinks you’re allycholly.
1630		Shakespeare Merry Wives of Windsor n.p.: [S]hee is giuen too much to Allicholy and musing.
1736		H. Walpole 30 May in Letters I (1891) 8: A disconsolate wood-pigeon in our grove, that was made a widow by the barbarity of a gun. She coos and calls me so movingly. [...] She is so allicholly as any thing.
1831		Navy at Home II 134: At this thought, a shade of ‘Allicholly’ [...] came over one and all.
1836		Bell’s Wkly Messenger 11 Dec. 398/1: So I fell allycholly, and I told my sorrowful sitivation to some of my old pals.