High:
1. Highness (noun) - the quality or state of being high; loftiness; elevation.
2. Highly (adverb) - to a high degree; greatly; extremely.
3. Heighten (verb) - to make or become higher or more intense.
4. High-rise (adjective) - relating to a tall building with many floors.
5. High-pitched (adjective) - having a high frequency or tone.

Sign:
1. Signify (verb) - to be an indication of; to represent or mean.
2. Significance (noun) - the quality of being important or meaningful.
3. Significant (adjective) - important; having a special meaning.
4. Signatory (noun) - a person or organization that has signed an official document.
5. Signify (verb) - to make a sign or gesture, especially to communicate something.