a. A social, legal, or moral requirement, such as a duty, contract, or promise, that compels one to follow or avoid a particular course of action: Are you able to meet your obligations? I have an obligation to attend their wedding.
b. The constraining power of a promise, contract, law, or sense of duty: I felt no obligation to offer my advice.
c. Law A document in which a person binds himself or herself to undertake or refrain from doing a particular act.
d. A debt instrument, such as a loan, mortgage, or bond.
2. The state, fact, or feeling of being indebted to another for a special service or favor received: If they invite us, aren't we under obligation to invite them in return?
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 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.