Basic forms:
* Sign: (noun) a mark, object, or gesture that conveys information or meaning.
* Signal: (noun) a sign or action that is used to convey information or instructions.
* Signature: (noun) a person's name written in their own handwriting, typically used to authenticate a document.
* Signify: (verb) to be a sign of; to mean.
Derived words:
* Design: (noun) a plan or drawing produced to show the look and function or workings of a building, garment, or other object before it is made. (Verb) to plan or create (something) with a specific purpose in mind.
* Assign: (verb) to allocate or designate (something) to a particular person or place.
* Resign: (verb) to give up a job or position.
* Consign: (verb) to entrust something to another person's care.
* Ensign: (noun) a flag flown at the stern of a ship.
* Insinuation: (noun) an indirect or subtle suggestion.
* Designation: (noun) the act of assigning or identifying something.
* Significant: (adjective) important or notable.
* Signature: (adjective) distinctive or characteristic.
This is not an exhaustive list, but it covers a wide range of words using the root "sign" in different contexts.