a. Having an intended or expected effect.
b. Producing a strong impression or response; striking: gave an effective performance as Othello.
2. Operative; in effect: The law is effective immediately.
3. Existing in fact; actual: a decline in the effective demand.
4. Prepared for use or action, especially in combat.
A soldier or a piece of military equipment that is ready for combat.
ef·fective·ness, ef′fec·tivi·ty n.
Synonyms: effective, effectual, efficacious
These adjectives mean producing or capable of producing a desired effect: an effective reprimand; an effectual complaint; an efficacious remedy.
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.