1. shadow; silhouette; figure; shape
光あれば影もありますね。Where there is light, there is also shadow.
2. reflection; image
3. ominous sign
町に戦争の影が迫っていた。The shadow of war was closing in on the town.
4. light (stars, moon)
5. trace; shadow (of one's former self)
もう影も形も残っていない。There's no trace of it left anymore.
6. behind; background; other side
non-standard; usu. written as 陰