sign in

Verb

sign in (third-person singular simple present signs in, present participle signing in, simple past and past participle signed in)

1. (idiomatic) To sign one's name on a list when entering a place, to indicate one's arrival.
   • In order to get into the office after hours, you'll have to sign in at the security desk.
   • Harper signed in with the rangemaster and handed him her gun. He reloaded it with six shells and handed it back, together with two sets of ear defenders.2007, Lee Child, Running Blind: A Jack Reacher Novel
2. To take some action to access a secured program or web page on a computer; to log in.
   • He signed in using his own cybername: Point Guard.1999, Jacqueline Guest, Triple Threat