Related Clues:

• Highway rig
• Kind of conductor
• Formal opening
• Sweet lead-in
• High-end car engine, for short
• Highway behemoth
• Part of a trucker's rig
• Engine option
• Formal introduction
• House type
• ''___-Tough''
• 50 percent (prefix)
• Prefix with "sphere"
• Prefix meaning "half"
• Final beginning?