Answer: thornier

AnswerCrossword Clue
THORNIERMore controversial or vexatious, as a problem.
THORNIERMore prickly
THORNIERMore complex
THORNIERLess solvable
THORNIERMore vexatious
thornierCausing distress, difficulty, or trouble
thornierTHORNY, full of thorns
thornierHaving many thorns or thorn bushes