1
tail and fins
2
embellishment (of a story, rumor, etc.);exaggeration
「学園の廊下で、濃厚なキスシーン・・・聞いたぞ聞いたぞ」「濃厚じゃなーい！話に尾ひれ付いてるって・・・」
"A passionate kiss scene in a school corridor ... I've heard all about it!" "It wasn't passionate! That's an exaggeration..."
Other forms
尾鰭 【おひれ】 · 尾ヒレ 【おひれ】