conversely; on the contrary; rather
Used to introduce a contrasting or opposite perspective, often to correct a previous assumption or to present an unexpected result. Can also soften a statement by framing it as the opposite of what was expected.
I thought he was angry, but on the contrary, he was pleased.
この薬は眠くなるどころか、逆に目が冴える。
Far from making you sleepy, this medicine actually makes you more alert.
順に means proceeding in the normal/set order, while 逆に means doing the same thing in reverse order.
Formed from 逆 (ぎゃく, 'reverse, opposite') + the adverbial particle に. The kanji 逆 is composed of 辶 (movement) and 屰 (inverted person), suggesting the idea of going against the expected direction.