These words mean to put off the some future time. Postpone usually suggests putting something aside until something else occurs, or is done, known, obtained, etc.

• The conference will be postponed until one week from next Friday; We are postponing our trip until the weather grows warmer.

However, postpone is often used without this limitation and may imply the intention of putting off an activity until some undetermined future time; to postpone planning for the future.

Adjourn is literally to postpone until another day or place. The word is customarily applied to a meeting of an organization or any formally constructed gathering, such as a legislative or deliberative body, which is brought to an end, especially with a view towards assembling again at a specified time or place.

• The hearing will be adjourned until tomorrow morning at ten o’clock; The House adjourns in time for the elections.

Delay means to postpone to an indefinite future time, usually because of obstacles that impede progress. It has the strong implication of lateness or tardiness. Often such obstacles are unavoidable: Their arrival will be delayed because of heavy traffic. On the other hand, delay may suggest failure to do something at the expected or proper time through either carelessness or reluctance: to delay fixing the roof although it leaked badly; to delay having an infected tooth pulled.

The suggestion of arbitrary lateness and putting off that resides in delay is absent from defer . Etymologically, defer means to refrain from dealing with, and implies the intentional delaying of an action in a more emphatic way than does postpone : to defer payment of one’s bills until the Christmas bonus is awarded.

Suspend , in this sense, is to discontinue or to withhold temporarily but indefinitely, pending the fulfilment of certain conditions.

• Bus service will be suspended until the highway is repaired; A scientist suspends judgement and refrains from drawing conclusions until all the facts are known.