Prorogue, v. t. [imp. & p. p. Prorogued; p. pr. & vb. n. Proroguing.]
Etymology: [F. proroger, L. prorogare, prorogatum; pro forward + rogare to ask, to ask one for his opinion or vote, or about a law. See Rogation.]
1. To protract; to prolong; to extend. [Obs.] He prorogued his government. Dryden.
2. To defer; to delay; to postpone; as, to proroguedeath; to prorogue a marriage. Shak.
3. To end the session of a parliament by an order of the sovereign, thus deferring its business. Parliament was prorogued to [meet at] Westminster. Bp. Hall. The Parliament was again prorogued to a distant day. Macaulay.
Syn. -- To adjourn; postpone; defer. See Adjourn.
Shades of meaning
Fernald lists prorogue only as an antonym, under convoke.
He lists it without comment; the entries above explain its neighbors.