put on hold/ice/the back burner, to

to put someone or someone's telephone call on an electronic hold. (See also put someone on hold.) Please don't put me on hold! I'm in a hurry! I am going to have to put your call on hold.

Fig. to stop all activity or communication with someone. (See also put someone or something on hold.) John put Ann on hold and started dating Mary. "You can't just put me on hold!" cried Ann.

to postpone something; to stop the progress of something. (See also put someone on hold; put someone or something on hold.) They put the project on hold until they got enough money to finish it. Sorry, but we must put your plan on hold.

To postpone, delay, keep in reserve. The oldest of these nearly synonymous terms is to put something on ice, the transfer from food storage (on ice blocks) to anything kept in reserve occurring in the late nineteenth century. Chefs put food that is either finished or cooks more quickly than the rest of a meal on a back burner of the range. By about 1930, this term was transferred to temporarily shelving any item or project or plan, originally in the United States, and came into general use about thirty years later. To put on hold also dates from the mid-twentieth century. It began to be used for the temporary interruption or suspension of a space launch and/or a telephone conversation. It was commonplace in both activities by about 1960 and was rapidly transferred to other kinds of delay, although its literal application—interrupting a telephone connection to wait for its resumption—is still current, along with the irritations generated by call waiting. See also your call is important.