As singed, Be careful about Singed's all-in capability, and his intent to displace you into his team. It can easily get you CC'd and killed.

Try not to chase him frequently in this matchup. Although your mobility is high, you will still take a lot of DPS from him.

Once you get your ult, make sure that you CC Singed every chance you get. Work with your team to take him down thereafter.

Keep the wave close to your tower. The enemy has no sort of sieging potential and can be easily exposed to ganks. As singed, Pay attention to Singed's complete ability, and his intention to move around with his team. He can easily make you CC'd and killed. Try not to pursue him frequently in this matchup. Although your mobility is high, you will always take a lot of DPS from him. Once you get your ult, make sure that you CC Singed all the chances you get. Work with your team to get him down after. Keep the wave near your turn. The enemy does not have some kind of sifting potential and can easily be exposed to the ganks.