curse

Etymology 1

From Middle English curse, kors, cors, curs, from Old English cors, curs (“curse”), of unknown origin.

noun

1. A supernatural detriment or hindrance; a bane.
2. A prayer or imprecation that harm may befall someone.
3. The cause of great harm, evil, or misfortune; that which brings evil or severe affliction; torment.
4. A vulgar epithet.
   Swearing doesn't just mean what we now understand by "dirty words". It is entwined, in social and linguistic history, with the other sort of swearing: vows and oaths. Consider for a moment the origins of almost any word we have for bad language – "profanity", "curses", "oaths" and "swearing" itself. 2013-06-14, Sam Leith, “Where the profound meets the profane”, in The Guardian Weekly, volume 189, number 1, page 37
5. (slang, dated, derogatory, usually with "the") A woman's menses.

Etymology 2

From Middle English cursen, corsen, coursen, from Old English corsian, cursian (“to curse”), from the noun (see above).

verb

1. (transitive) To place a curse upon (a person or object).
2. To call upon divine or supernatural power to send injury upon; to imprecate evil upon; to execrate.
3. (transitive) To speak or shout a vulgar curse or epithet.
4. (intransitive) To use offensive or morally inappropriate language.
5. To bring great evil upon; to be the cause of serious harm or unhappiness to; to furnish with that which will be a cause of deep trouble; to afflict or injure grievously; to harass or torment.