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

fasten (fastens, present participle fastening; 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 seatbelts!

   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, William Shakespeare, “The Tragedie of Othello, the Moore of Venice”, in Mr. William Shakespeares Comedies, Histories, & Tragedies: Published According to the True Originall Copies (First Folio), London: Printed by Isaac Iaggard, and Ed[ward] Blount, published 1623, OCLC 606515358 ↗, [Act II, scene iii]:

     if I can fasten but one cup upon him

• bedfast
• breastfast
• colorfast
• cragfast
• fast
• handfast
• headfast
• holdfast
• makefast
• sitfast
• shamefast
• soothfast
• steadfast

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