Related Clues:

• Stiff-backed
• Not slouching
• Vertical
• Full of hubris
• In a vertical position
• Gratified
• Like Cro-Magnon man
• Build, as a building
• Haughty
• Like squirrels' ears
• Hardly humble
• Word in a Marines slogan
• Like an attentive dog's ears
• Build, as a skyscraper
• Have fun with Lego blocks