To put something on ice means to delay something until some point in the future. To postpone something. Usuall, this refers to something you have to do. Often, this is something that that you are currently doing or something you had planned to do now but, for some reason, you aren't able to finish it now or it would make more sense to do it later. A husband might say to his wife something like, "Sorry, Honey. Something came up at work, so we'll have to put our plans for the weekend on ice." In this case, the husband and wife had planned to do something, but will have to postpone it till some other time. In the following example, a group of employees has been meeting for some time, but is getting nowhere. They decide to stop for now and resume at a later date when the people might have some fresh ideas.
Mr. Drake: So, does anyone have any other ideas? We've been talking about this for four hours now.
Robert: Sorry, sir. My brain isn't functioning any more.
Mr. Drake: Alright, people. Let's put this on ice for now and meet again next week. In the meantime, be sure to think of some new ideas.
This phrase come from the fact that, if you weren't going to eat something right away, you could put it on a block of ice (in the icebox or ice house–Nowadays you would use the refridgerator or freezer) and save it for later.



