To tentatively make an appointment or commitment. Implies it could be changed or canceled, since pencil marks are erasable.
Bob: "I got tickets to Saturday's game. You want to go?"
Tom: "If I can. I might have to work that day, but I'll pencil you in."
by Aaron of Minneapolis May 10, 2010
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This is what a person says when he is making a tentative appointment.

"I'll Pencil" (because the appointment can be erased) "you in" (to my schedule book).
Ozzy: Hey, can I come up to your big fancy office and make fun of you?
Boohiss: Er. I'm kinda busy this week. Tell you what, I'll pencil you in for 4:30 on Thursday.
by boohiss May 20, 2004
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When somebody wants to schedule something with you, but you don't want to use a pen to finalize it in your calendar because that person is a loser. If something better comes along -- you can erase it.
Sure, I'd love to watch slides from your trip to the Grand Canyon -- I'll pencil you in.
by Kid May 20, 2004
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Girl: Want to go out friday night? I'll bring pictures of my horse!
Guy: ...Um....I'll Pencil You In.
by BlackCotton May 20, 2004
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To schedule someone for a meeting.
To enter an appointment into an appointment book with pencil.
I'll pencil you in for a meeting.
by Pencil DIck May 20, 2004
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Informal idiom meaning to make an appointment for someone; to "pencil them in" to the schedule.
"Can I see the doctor right away?"
"No, but I can pencil you in for a two o'clock appointment."
by Hobo Bob May 19, 2004
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