Longman Dictionary of Contemporary English
The Collaborative International Dictionary
Constitutionalism \Con`sti*tu"tion*al*ism\
(k[o^]n`st[ict]*t[=u]"sh[u^]n*al*[i^]z'm), n.
The theory, principles, or authority of constitutional
government; attachment or adherence to a constitution or
constitutional government.
--Carlyle.
Douglas Harper's Etymology Dictionary
1832, "constitutional system of government;" occasionally also "constitutionality;" from constitutional (adj.) + -ism.
Wiktionary
n. Philosophical belief in government under a written constitution.
WordNet
n. a constitutional system of government (usually with a written constitution)
advocacy of a system of government according to constitutional principles
Wikipedia
Constitutionalism is "a complex of ideas, attitudes, and patterns of behavior elaborating the principle that the authority of government derives from and is limited by a body of fundamental law".
Political organizations are constitutional to the extent that they "contain institutionalized mechanisms of power control for the protection of the interests and liberties of the citizenry, including those that may be in the minority". As described by political scientist and constitutional scholar David Fellman:
Usage examples of "constitutionalism".
It does not pit section against section, the States severally against the General government, nor the General government against the State governments, and nothing is more hurtful than the attempt to explain it and work it on the principles of British constitutionalism.
This may, indeed, be changed, but only to substitute for imperial centralism democratic centralism, which were no improvement, or to go back to the system of antagonisms, checks and balances, called constitutionalism, or parliamentary government, of which Great Britain is the model, and which were a return toward barbarism, or mediaeval feudalism.
Ecclesiasticism and Constitutionalism send us one way, Protestantism and Anarchism the other.
And since, on this world-embracing scale, it was clear that Siegfried must come into conflict with many baser and stupider forces than those lofty ones of supernatural religion and political constitutionalism typified by Wotan and his wife Fricka, these minor antagonists had to be dramatized also in the persons of Alberic, Mime, Fafnir, Loki, and the rest.