Pocket Dial Meaning

(obsolete) A portable sundial of small size.

Example: 2013, Jess McCann, Was It Something I Said?: The Answer To All Your Dating Dilemmas, Skirt! (2013), ISBN 9780762791705, pages 7-8:
  But consider this first: How do you know that he really meant to call you and this wasn't just an accidental pocket dial?
2013, Elle Fowler & Blair Fowler, Where Beauty Lies, St. Martin's Press (2013), ISBN 9781250006196, page 60:
  It started off sounding like a pocket dial with incoherent noise and shouting […]
2015, Abbi Glines, Hold On Tight, Simon Pulse (2015), ISBN 9781481420815, pages 95-96:
  My phone started ringing. I reached over and grabbed it, surprised to see Dewayne's name on the screen. Why would he be calling me at midnight on a Saturday?
  "Hello?" I said, almost expecting this to be a pocket dial.