duress

n. intimidation, constraint, coercion, pressure

For English law on the criminal defence, see duress in English law. For contract law, see Duress (contract law) Duress or coercion (as a term of jurisprudence) is a possible legal defense, usually as an excuse rather than a justification, by which defendants argue that they should not be held liable because the actions that broke the law were only performed out of an immediate fear of injury. Black's Law Dictionary (6th ed.) defines duress as "any unlawful threat or coercion used... to induce another to act [or not act] in a manner [they] otherwise would not [or would]." The notion of duress must be distinguished both from undue influence in the civil law and from necessity which might be described as a form of duress by force of circumstances.
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Noun
1. compulsory force or threat; "confessed under duress"
(hypernym) force

(v. t.)
To subject to duress.
  

(n.)
The state of compulsion or necessity in which a person is influenced, whether by the unlawful restrain of his liberty or by actual or threatened physical violence, to incur a civil liability or to commit an offense.
  

(n.)
Hardship; constraint; pressure; imprisonment; restraint of liberty.
  

Where a person is prevented from acting (or not acting) according to their free will, by threats or force of another, it is said to be 'under duress'. - (read more on Duress)