1) Bird genus 2) Genus otus 3) Giant slain by Apollo 4) Social networking service 5) Victim of Apollo 
HMS Otus was a British Olympus Class submarine of 1475 tons displacement launched in 1928. She was armed with one 4-inch gun; two machine-guns; six 21-inch torpedo tubes in the bow and two 21-inch torpedo tubes in the stern. She had a top speed of 17.5 knots on the surface, 9 knots submerged and carried a complement of 50.
[n] - a genus of Strigidae
genus Otus noun a genus of Strigidae