What is 'hold' please?

[BookBint]

Ring ring

BB: OddlyGeekyHistoryPublishingCompany, BookBint speaking.
SC: Ah hello BookBint, is <UberBoss> there?
BB: Oh hello <OldCrotchetyAuthor>, <UberBoss> is away from his desk at the moment *outside having a smoke*. Is it urgent, I can see if I can find him if you want?
SC: Oh yes dear, please do.
BB: Ok, well I'll just put you on hold, ok?
SC: Yes yes, fine.

Put phone on hold, lean out of window, bellow '<UberBoss! <OldCrotchetyAuthor> is on the phone!' <UberBoss> grunts and stubs out his cigarette. I pick up the phone and remove hold.

BB: Hello? <UberBoss> is just coming.
SC: WHAT HAPPENED????????????
BB: Excuse me?
SC: Did you put the phone down on me? I was saying your name but you didn't answer!
BB: Uh, I put you on hold, sorry, I thought I said that's what I would do...
SC: But I didn't know it meant that!!!!!
BB: What, 'hold'??
SC: How terribly rude!
BB: I am very sorry... *you technologically retarded man. Have you never rung your bank? They luuurve putting you on hold*

<UberBoss> returned and the author complained that I was very rude and that I had put him on something called 'hold' and that he was rather put out. <UberBoss> grunted and told him his manuscript was late.

[lineswine]

Ring ring

"the author complained that I was very rude and that I had put him on something called 'hold' and that he was rather put out.

Dude, the 1930's called (on a candlestick phone, no less) - they want their phone exchange back.