アポなし

noun which may take the genitive case particle 'no'

without an appointment

Used when someone shows up or contacts without a prior appointment; often carries a nuance of being unexpected or informal.

See also: アポ

• アポなしで会かい社しゃに行いくのはやめてください。

  Please don't go to the office without an appointment.

• 彼かれはいつもアポなしで訪たずねてくる。

  He always drops by without an appointment.