In the Modern Language Association (MLA) style of citation, you do not generally need to cite a dictionary as a standalone source. This is because dictionaries are considered to be reference materials that provide general background information and definitions of words, rather than sources of original research or ideas.
However, if you are using a specific definition from a dictionary in your paper, you should provide a citation for the source. You can do this by including the word and its definition in quotation marks, followed by the name of the dictionary and the publication information in parentheses. For example:
"Effervescence" is defined in the Oxford English Dictionary as "the action of bubbling up or giving off bubbles; fizziness" (Oxford English Dictionary).
Alternatively, you could include the definition in your own words and provide a citation for the dictionary in the Works Cited list at the end of your paper. In this case, you would include the name of the dictionary, the publisher, and the date of publication in the citation.
Overall, it is important to provide proper citations for any sources that you use in your research, including dictionaries, to give credit to the original authors and to help your readers locate the sources you have used. This practice helps to ensure that your work is scholarly and reliable, and it also helps to prevent plagiarism.