1. An important weakness or flaw in someone who appears strong or invincible

Encyclopedia: Feet of clay

• unsightliness
• unsightly
• unsigned
• unsilenced
• unsimilarity
• unsinkable
• unsized
• unskilful
• unskilfulness
• unskilled
• unskilled person
• unskillful
• unskillfulness
• unslaked lime
• unsleeping
• unsling
• unsloped
• unsmiling
• unsmilingly
• unsmooth
• unsmoothed
• unsnarl
• unsnarled
• unsnarling
• unsociability