lock on

• (UK) IPA^(key): /ˌlɒk ˈɒn/
• (US) IPA^(key): /ˌlɑk ˈɑn/

lock on (third-person singular simple present locks on, present participle locking on, simple past and past participle locked on)

1. (intransitive) To begin tracking a target via an automated system.
   • 1997, Phil Husbands, Inman Harvey, Fourth European Conference on Artificial Life, page 356:

     When the triangle came into view, the robot would then 'lock on' and move directly towards it, adjusting its course as it went.

   • 2013, Jim Keys, Fighting Brits, page 255:

     Glasgow's Sea Darts failed to lock on to the attackers, but the Sea Wolfs from Brilliant shot down one Skyhawk while another attacker crashed while trying to evade the missiles.

2. (transitive) To cause a missile to track (a target).
3. (intransitive) To engage in a lock-on protest.