From Middle English fastenen, from Old English fæstnian, from Proto-West Germanic *fastinōn.

• (RP) IPA: /ˈfɑːsən/, /ˈfɑːsn̩/
• (America) IPA: /ˈfæsən/, /ˈfæsn̩/

fasten (fastens, present participle fastening; simple past and past participle fastened)

1. (ambitransitive) To attach or connect in a secure manner.

   The sailor fastened the boat to the dock with a half-hitch.

   Fasten your seat belts!

   Can you fasten these boards together with some nails?

   • May 31, 1711, Jonathan Swift, The Examiner No. 43

     The words Whig and Tory have been pressed to the service of many successions of parties, with very different ideas fastened to them.

2. To cause to take close effect; to make to tell; to land.

   to fasten a blow

   • c. 1603–1604 (date written), William Shakespeare, “The Tragedie of Othello, the Moore of Venice”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC ↗, [Act II, scene iii]:

     if I can fasten but one cup upon him

• French: attacher, fixer
• German: befestigen, festmachen
• Portuguese: apertar, atar, firmar, segurar
• Russian: закрепля́ть
• Spanish: atar, abrochar