trenchant in WordNet English dictionary

1. clearly or sharply defined to the mind
   "clear-cut evidence of tampering"; "Claudius was the first to invade Britain with distinct...intentions of conquest"; "trenchant distinctions between right and wrong"
   clear-cut  distinct  trenchant 
   
2. characterized by or full of force and vigor
   "a hard-hitting expose"; "a trenchant argument"
   hard-hitting  trenchant 
   
3. having keenness and forcefulness and penetration in thought, expression, or intellect
   "searching insights"; "trenchant criticism"
   searching  trenchant