1. The action or purpose for which a person or thing is suited or employed, especially:
a. A person's role or occupation: in my function as chief editor.
b. Biology The physiological activity of an organ or body part: The heart's function is to pump blood.
c. Computers A procedure within an application.
2. An official ceremony or a formal social occasion: disliked attending receptions and other company functions.
3. Something closely related to another thing and dependent on it for its existence, value, or significance: Growth is a function of nutrition.
4. Abbr. f Mathematics
a. A variable so related to another that for each value assumed by one there is a value determined for the other.
b. A rule of correspondence between two sets such that there is exactly one element in the second set assigned to each element in the first set. Also called mapping.
intr.v. func·tioned, func·tion·ing, func·tions
1. To have or perform a function; serve: functioned as ambassador.
2. To deal with or overcome the challenges of everyday life: For weeks after his friend's funeral he simply could not function.
[Latin fūnctiō, fūnctiōn-, performance, execution, from fūnctus, past participle of fungī, to perform, execute.]
Synonyms: function, duty, office, role
These nouns denote the actions and activities assigned to, required of, or expected of a person: the function of a teacher; a bank clerk's duty; performed the office of financial adviser; the role of a parent.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.