adj

• (archaic) Trivial; insignificant.
  "‘That was a symple cause,’ seyde Sir Trystram, ‘for to sle a good knyght for seyynge well by his maystir.’"
• (now colloquial, euphemistic) Feeble-minded; foolish.
• (heading, technical) Structurally uncomplicated.
• (heading, technical) Structurally uncomplicated.

noun

• (pharmacology) A herbal preparation made from one plant, as opposed to something made from more than one plant.
  "Dere is some simples in my closet, dat I vill not for the varld I shall leave behind."
• (obsolete, by extension) A physician.
• (logic) A simple or atomic proposition.
  "Peter van Inwagen, for example, believes that there are no ordinary objects, no chairs or shirts or shoes. Right here there are just some simples — atoms or whatever — arranged shoe-wise."
• (obsolete) Something not mixed or compounded.
  "But it is a melancholy of mine own, compounded of many simples, extracted from many objects, and indeed the sundry contemplation of my travels"

verb

• (transitive, intransitive, archaic) To gather simples, i.e. medicinal herbs.