thorny (adj.) Look up thorny at Dictionary.com
Old English þornig; see thorn + -y (2). Figurative sense is attested from mid-14c. Related: Thorniness. Similar formation in Dutch doornig, German dornig. The figurative image is widespread; Greek had akanthologos as a nickname for a quibbler, literally "thorn-gathering," and akanthobates, nickname for a grammarian (fem. akanthobatis).