1. Having or composed of only one thing, element, or part. See synonyms at pure.
2. Not involved or complicated; easy: a simple task. See synonyms at easy.
3. Being without additions or modifications; mere: a simple "yes" or "no."
4. Having little or no ornamentation; not embellished or adorned: a simple dress.
5. Not elaborate, elegant, or luxurious. See synonyms at plain.
6. Unassuming or unpretentious; not affected.
7. 1. Having or manifesting little sense or intelligence.
   2. Uneducated; ignorant.
   3. Unworldly or unsophisticated. See synonyms at naive.
8. Not guileful or deceitful; sincere.
9. Humble or lowly in condition or rank: a simple woodcutter.
10. Ordinary or common: a simple head cold.
11. 1. Being a fundamental or rudimentary element; basic.
    2. Not important or significant; trivial.
12. Biology. Having no divisions or branches; not compound: a simple leaf; a simple eye or lens.
13. Music. Being without figuration or elaboration: a simple tone.

1. A single component of a complex, especially one that is unanalyzable.
2. A fool; a simpleton.
3. A person of humble birth or condition.
4. A medicinal plant or the medicine obtained from it.

[Middle English, from Old French, from Latin simplus and from simplex; see simplex.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.