I guess a slut would be a woman who sleeps around and has no feelings or respect for her men or for herself. And probably the woman herself would have to be the one who decides if she is a slut.

From Dictionary.com:

Quote:
Dictionary.com Unabridged (v 1.1) - Cite This Source
slut /slʌt/ Pronunciation Key - Show Spelled Pronunciation[sluht] Pronunciation Key - Show IPA Pronunciation
–noun 1. a dirty, slovenly woman.
2. an immoral or dissolute woman; prostitute.


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[Origin: 1375–1425; late ME slutte; cf. dial. slut mud, Norw (dial.) slutr sleet, impure liquid]
Dictionary.com Unabridged (v 1.1)
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2006.
American Heritage Dictionary - Cite This Source slut (slŭt) Pronunciation Key
n.

A person, especially a woman, considered sexually promiscuous.
A woman prostitute.
A slovenly woman; a slattern.


[Middle English slutte.]

slut'tish adj., slut'tish·ly adv., slut'tish·ness n., slut'ty adj.

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Copyright © 2006 by Houghton Mifflin Company.
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Online Etymology Dictionary - Cite This Source
slut

1402, "a dirty, slovenly, or untidy woman," probably cognate with dialectal Ger. Schlutt "slovenly woman," dialectal Swed. slata "idle woman, slut," and Du. slodder "slut," but the ultimate origin is doubtful. Chaucer uses sluttish (c.1386) in ref. to the appearance of an untidy man. Also "a kitchen maid, a drudge" (c.1450; hard pieces in a bread loaf from imperfect kneading were called slut's pennies, 18c.). Meaning "woman of loose character, bold hussy" is attested from c.1450; playful use of the word, without implication of loose morals, is attested from 1664.
"Our little girl Susan is a most admirable slut, and pleases us mightily." [Pepys, diary, Feb. 21, 1664]
Sometimes used 19c. as a euphemism for bitch to describe a female dog. There is a group of North Sea Gmc. words in sl- that mean "sloppy," and also "slovenly woman," and that tend to evolve toward "woman of loose morals" (cf. slattern, also Eng. dial. slummock "a dirty, untidy, or slovenly person," 1861; M.Du. slore "a sluttish woman").

Online Etymology Dictionary, © 2001 Douglas Harper


Wikipedia has a really long entry [ http://en.wikipedia.org/wiki/Slut ], but makes this useful distinction in one of the sections:
Quote:
...identify a slut as a person of low character — a person who lacks the ability or chooses not to exercise a power of discernment to order their affairs


To me, sleeping with a guy because he's cute indicates discernment, and thus disqualifies the woman who does it as a slut. ;\)