1. Lacking nothing essential to the whole; complete of its nature or kind.
2. Being without defect or blemish: a perfect specimen.
3. Thoroughly skilled or talented in a certain field or area; proficient.
4. Completely suited for a particular purpose or situation: She was the perfect actress for the part.
a. Completely corresponding to a description, standard, or type: a perfect circle; a perfect gentleman.
b. Accurately reproducing an original: a perfect copy of the painting.
6. Complete; thorough; utter: a perfect fool.
7. Pure; undiluted; unmixed: perfect red.
8. Excellent and delightful in all respects: a perfect day.
9. Botany Having both stamens and pistils in the same flower; monoclinous.
10. Capable of sexual reproduction. Used of fungi.
11. Grammar Of, relating to, or constituting a verb form expressing action completed prior to a fixed point of reference in time.
12. Music Designating the three basic intervals of the octave, fourth, and fifth.
1. Grammar The aspect of a verb that expresses action completed prior to a fixed point of reference in time.
2. A verb or verb form having this aspect.
tr.v. (pər-fĕkt) per·fect·ed, per·fect·ing, per·fects
To bring to perfection or completion: perfected the technique to isolate the virus.
[Middle English perfit, from Old French parfit, from Latin perfectus, past participle of perficere, to finish : per-, per- + facere, to do; see dhē- in the Appendix of Indo-European roots.]
Synonyms: perfect, consummate, faultless, flawless, impeccable
These adjectives mean being wholly without flaw: a perfect diamond; a consummate performer; faultless logic; a flawless instrumental technique; speaks impeccable French.
Usage Note: The adjective perfect is often considered an absolute term like chief and prime; some maintain that it therefore cannot be modified by more, quite, relatively, and other qualifiers of degree. But the qualification of perfect has many reputable precedents (most notably in the preamble to the US Constitution in the phrase “in order to form a more perfect Union”). When perfect means “ideal for a purpose,” as in There could be no more perfect spot for the picnic, modification by degree is considered acceptable; in fact 74 percent of the Usage Panel approved this example in our 2004 survey. See Usage Notes at absolute, equal, unique.
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.