Postpone, v. t. [imp. & p. p. Postponed; p. pr. & vb. n. Postponing.]
Etymology: [L. postponere, postpositum; post after + ponere to place, put. See Post-, and Position.]
1. To defer to a future or later time; to put off; also, to cause to be deferred or put off; to delay; to adjourn; as, to postpone the consideration of a bill to the following day, or indefinitely. His praise postponed, and never to be paid. Cowper.
2. To place after, behind, or below something, in respect to precedence, preference, value, or importance. All other considerations should give way and be postponed to this. Locke.
Syn. -- To adjourn; defer; delay; procrastinate.
Shades of meaning
Fernald has no entry of its own for postpone; he lists it under protract.
Where he writes about it:
Postpone implies a definite intention to resume, as defer also does, though less decidedly; both are often used with some definite limitation of time; as, to postpone till, until, or to a certain day or hour. — from protract
One may defer, delay, or postpone a matter intelligently and for good reason; he procrastinates through indolence and irresolution. — from protract