A passcode is a secret combination of numbers or words that you use to unlock something or gain access to it. It's like a password that keeps something secure and only lets authorized people use it. Full definition
Make sure that you enter passcode on watch and not on iPhone. (indabaa.com)
After using Touch ID, I found it annoying to go back to typing in passcodes on my older iPhone.» (iphonehacks.com)
I love using my Apple Watch to open my door when I get home, and it's great for our in - home daycare because I can set passcodes for all the parents during daycare hours and they can easily let themselves in and go downstairs to drop off or pick up their kid. (macrumors.com)