From Middle English mornen, mournen, from Old English murnan, from Proto-Germanic *murnaną.

• (America) enPR: môrn, IPA: /mɔɹn/
• (RP) enPR: môn, IPA: /mɔːn/
• (rhotic, non-horse-hoarse) enPR: mōrn, IPA: /mo(ː)ɹn/
• (non-rhotic, non-horse-hoarse) IPA: /moən/
• (rare, rhotic, with or without the <>) enPR: mo͝orn, IPA: /mʊɹn/
• (rare, non-rhotic, with or without the <>) enPR: mo͝orn, IPA: /mʊən/

mourn (mourns, present participle mourning; simple past and past participle mourned)

1. (ambitransitive) To express sadness or sorrow for; to grieve over (especially a death).
   • 1591 (date written), William Shakespeare, “The First Part of Henry the Sixt”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC ↗, [Act I, scene i]:

     We mourn in black; why mourn we not in blood?

   • 1611, The Holy Bible, […] (King James Version), London: […] Robert Barker, […], →OCLC ↗, Genesis 23:2 ↗:

     Abraham came to mourn for Sarah, and to weep for her.

2. (transitive) To utter in a sorrowful manner.
3. (intransitive) To wear mourning.

• French: déplorer, porter le deuil
• German: trauern
• Italian: rimpiangere, essere (in) lutto
• Portuguese: lamentar, estar de luto
• Russian: горева́ть
• Spanish: lamentar, estar de luto, penarse

mourn

1. (now literary) Sorrow, grief.
   • 1485, Sir Thomas Malory, “[https://quod.lib.umich.edu/c/cme/MaloryWks2/1:4.12?rgn=div2;view=fulltext vij]”, in Le Morte Darthur, book II:

     Anone after ther cam balen / and whan he sawe kynge Arthur / he alyght of his hors / and cam to the kynge on foote / and salewed hym / by my hede saide Arthur ye be welcome / Sire ryght now cam rydynge this way a knyght makynge grete moorne / for what cause I can not telle

     (please add an English translation of this quotation)

2. A ring fitted upon the head of a lance to prevent wounding an adversary in tilting.