Peculiar
Unusual, Odd
noun, な adjective
The kanji and the word are exactly the same. That means they share meanings as well.
Note that 妙 is more often used in writing than conversation.
The reading is actually the same as the kanji you learned. On'yomi all the way, despite being all alone. How peculiar!
コウイチは、妙なステッカーを車にはっている。
Koichi has a strange sticker on his car.
下山さんって、妙に理屈屋な時があるよね。
Mr. Shimoyama can be strangely argumentative at times.
妙だな。いつもならこの時間には母親から電話がかかってくるんだけど。
Strange. I usually get a call from my mother at this time.