In countries like the United States, there is a particular time period which, if not unanimously and precisely, can be generally referred to as the American Revolution. Certainly no one would say that the current government could be referred to as revolutionary. However, I commonly hear of countries such as Iran and Cuba which consider themselves to still be revolutionary and in which individuals can be prosecuted for opposing the revolution. How is it that these countries can call what has essentially become the entrenched form of government revolutionary? Is it a misnomer or is there a particular definition of which I am ignorant that allows for a regime which is more than half of a century old too be considered revolutionary?
The short answer is no. This is part of the reason why revolutions have so much stuff published about them - e.g. American Revolution, American Civil War, English Civil War(s), French Revolution(s), Russian Revolution(s), Mexican Revolution, et al. The first difficulty is defining the term "revolution."
Is it a revolution if the movement fails? Does it end if it is successful? If it is successful, does it really constitute revolution, or is it the growth of a popular progressive movement no longer in line with the status quo? How many people have to be involved? What's the difference between rebellion, revolt, and revolution? Is there a general pattern to revolution? Does a revolution have to be violent? Does a revolution necessarily involve politics and social movements, or can you have an "agricultural revolution" or "scientific revolution" or "industrial revolution"?
This is a brief list of typical questions asked concerning revolutions. There have been many attempts to answer these questions, some of which will sound reasonable, depending upon your own point of view, but there is no definite answer.
If you define and defend your position on what constitutes a "revolution" well you may have a few or a lot of people (i.e. scholars) that may agree with you, but nothing approaching consensus. Part of the difficulty of countries or powerful groups defining themselves as revolutionary is that generally a revolution results in a usurpation of the status quo. If the old regime has been thrown out of power and the revolutionary regime put into power, is the new status quo revolutionary? Or does the definition of revolution now shift to something different because a new group is in power? It's a tough, tough, question to answer, and other on this subreddit who study revolutionary periods and movements will doubtless have their own opinions, and you should form your own, too.
Here are a few works on revolutions and revolutionary thought that you may find useful:
(1) Karl Mannheim. Ideology and Utopia (1936)
(2) Eric Hobsbawm. The Age of Revolution: Europe 1789-1848 one of the classic works on the subject.
(3) Eric Hobsbawm. Revolutionaries: Contemporary Essays (1973)
(4) Karl Marx and Friedrich Engels. The Marx-Engels Reader (1978)
(5) Gary Kates. The French Revolution : recent debates and new controversies (2002)
(6) Wensun Xie. Chinese historiography on the Revolution of 1911 : a critical survey and a selected bibliography (1975)
(7) Steve Pincus. 1688 : the first modern revolution (2009)
(8) Damián J Fernández. Cuban studies since the revolution (1992)
(9) Edward Acton. Critical companion to the Russian Revolution, 1914-1921 (1997)
(10) N.H. Keeble. The Cambridge companion to writing of the English Revolution (2001)
(11) Adam Ulam. Ideologies and illusions : revolutionary thought from Herzen to Solzhenitsyn (1976)
(12) Antonio Gramsci. The Prison Notebooks
(13) Jack Goldstone. Revolutions: A Very Short Introduction (2013)
(14) Barrington Moore. *Social Origins of Dictatorship and Democracy: Lord and Peasant in the Making of the Modern World * (1966)
(15) Charles Tilly. European Revolutions, 1492–1992 (1993)
(16) Charles Tilly. Social Movements, 1768–2008, 2nd edition (2009)
This should be enough to get you started.
Hope this helps a little. Happy reading!