Simple

1. Uncomplicated; taken by itself, with nothing added.
2. Easy; not difficult.
3. Without ornamentation; plain.
4. Free from duplicity; guileless, innocent, straightforward.
5. Undistinguished in social condition; of no special rank. Antonym: gentle
6. (archaic) Trivial; insignificant.
7. (now colloquial, euphemistic) Feeble-minded; foolish.
8. (heading, technical) Structurally uncomplicated.
   1. (chemistry, pharmacology) Consisting of one single substance; uncompounded.
   2. (mathematics) Of a group: having no normal subgroup.
   3. (botany) Not compound, but possibly lobed.
   4. (of a steam engine) Using steam only once in its cylinders, in contrast to a compound engine, where steam is used more than once in high-pressure and low-pressure cylinders.
   5. (zoology) Consisting of a single individual or zooid; not compound.
   6. (mineralogy) Homogenous.
9. (obsolete) Mere; not other than; being only.

Synonyms

• (consisting of a single part or aspect): onefold
• (having few parts or features): basic, plain, uncomplex, uncomplicated

Antonyms

• (having few parts or features): complex, compound, complicated
• (uncomplicated): subtle