1. Intellectually or emotionally overwhelming
   "a mind-boggling display"; "a mind-boggling puzzle"

See also: impressive

• triple point
• triple sec
• triple time
• triple-crown
• triple-crown season
• triple-decker
• triple-space
• triple-spacing
• triple-tongue
• triplet
• triplet code
• tripletail
• Tripleurospermum
• Tripleurospermum inodorum
• Tripleurospermum oreades tchihatchewii
• Tripleurospermum tchihatchewii
• triplex
• triplicate
• triplication
• triplicity
• tripling
• Triplochiton
• Triplochiton scleroxcylon
• triploid
• triply