shit

First recorded before 900; (verb) variant (with short i from past participle or noun) of earlier shite, Middle English shiten, Old English scītan; compare Middle Low German, Middle Dutch schiten (Dutch schijten ), Old High German skīzan (German scheissen ); (noun) re-formation from the verb, or continuation of Old English scite (in placenames)

Even though shit has lost much of its shock value through frequent use, language experts continue to caution against indiscriminately using the word, and still label it as vulgar or coarse.
The word has numerous meanings and occurs in many colorful phrases and compounds that have nothing to do with defecation: for example, no shit, shit happens, and shitfaced.
In informal conversations among friends, the use of shit and its various expressions is often acceptable. For some people, the word comes naturally, without hesitation, as an expression of annoyance or chagrin, even if they still find it too vulgar to use in its literal sense. But in formal settings, use of the word generally remains inappropriate.