pen in

present singular third person pens in · participle present penning in · participle past penned in · past penned in

1. To enclose (animals) in a pen.
   1. broadlyfigurativelyTo cause to be stuck in a situation; to be forced into a situation by circumstances.
2. To schedule; fix a date for.

   So check this out, take out your planner, pen it in, and pass it on!

   2013, Tammy Lynn Robinson, Thoughts of the Heart: POEMS, PRAYERS AND PASSIONS, →ISBN, page 22

   3 more examples

   She wanted to say regardless of who got the contract, they should get out a calendar and pen it in.

   2012, Robin Bielman, Worth the Risk, →ISBN

   That's what I encourage you to do, too: pick a time with your partner that will generally work for both of you and pen it in to your calendars, bearing in mind that you will probably need to adjust it every now and then.

   2012, Susan Downing, The Heart of Reiki, →ISBN, page 31

   In fact, Peters had to pen in the date himself to mark the visit to the murderous mother in the hospital since he misentered it under March 16 instead of the fourteenth.

   2013, Molly A. McCarthy, The Accidental Diarist: A History of the Daily Planner in America, →ISBN