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de·fend (dĭ-fĕnd)
v. de·fend·ed, de·fend·ing, de·fends
a. To make or keep safe from danger, attack, or harm: a vaccine to defend the body from infection.
b. To engage in or be prepared to engage in battle to prevent (a population or area, for example) from being captured or occupied by an enemy.
2. Sports
a. To attempt to prevent the opposition from scoring while playing in or near (a goal or area of a field, for example).
b. To be responsible for guarding (an opposing player).
3. To compete against a challenger in an attempt to retain (a championship).
4. To support or maintain, as by argument or action; justify: defended his friend's behavior.
5. Law
a. To represent (a defendant) in a civil or criminal action.
b. To attempt to disprove or invalidate (the claim made by a lawsuit or prosecution): defend a class action; defend a criminal case.
1. To make a defense.
2. Sports To play defense.

[Middle English defenden, from Old French defendre, from Latin dēfendere, to ward off; see gwhen- in the Appendix of Indo-European roots.]

de·fenda·ble adj.
de·fender n.

Synonyms: defend, protect, guard, preserve, shield, safeguard
These verbs mean to make or keep safe from danger, attack, or harm. Defend implies repelling or being ready to repel an attack: The army defended the border against the enemy. The politician responded quickly to defend his reputation.
Protect often suggests keeping something safe by coming between it and any threat of harm or injury: Police protected the stores from looters. Sunglasses protect your eyes.
Guard suggests keeping watch: Their dog guarded the house against intruders.
To preserve something is to protect it from future harm or alteration: An environmental group purchased the wetland to preserve it from commercial development.
Shield suggests providing a barrier against something dangerous or destructive: "Grant's remaining units made their way through heavy timber ... in turn, however, the woods shielded them from Confederate bullets until they were almost on top of the enemy line" (Brooks D. Simpson).
Safeguard implies the vigilant protection of something of great value or importance: The Bill of Rights safeguards our individual liberties.

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. 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:

    Indo-European Roots

    Semitic Roots

    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.