apex /āˈpeks/

1. The summit, tip or point
2. A vertex (geometry)
3. The culminating point or climax of anything

• thoroughest
• thoroughfare
• thoroughfares
• thoroughgoing
• thoroughgoingly
• thoroughgoingness
• thoroughly
• thoroughness
• thoroughnesses
• thorough-paced
• thoroughpin
• thoroughs
• thoroughwax
• thoroughwaxes
• thorow-wax
• thorp
• thorpe
• thorpes
• thorps
• those
• those were the days
• Thoth
• thother
• thou
• thou'd