fuck

Origin:

early 16th century: of Germanic origin (compare Swedish dialect focka and Dutch dialect fokkelen); possibly from an Indo-European root meaning 'strike', shared by Latin pugnus 'fist'

Despite the wideness and proliferation of its use in many sections of society, the word fuck remains (and has been for centuries) one of the most taboo words in English. Until relatively recently it rarely appeared in print; even today, there are a number of euphemistic ways of referring to it in speech and writing, e.g. the F-word, f***, or f—k.