c.1600, "diversion of attention," especially in military actions, from French amusement, noun of action from amuser (see amuse).
And because all bold and irreverent Speeches touching matters of high nature, and all malicious and false Reports tending to Sedition, or to the Amusement of Our People, are punishable ... (etc.) [Charles II, Proclamation of Oct. 26, 1688]Meaning "a pastime, play, game, anything which pleasantly diverts the attention" (from duty, work, etc.) is from 1670s, originally depreciative; meaning "pleasurable diversion" attested from 1690s. Amusement hall is from 1862; amusement park first recorded 1897.