Misc: who was the us president in 1808?

Questions

A person who translates orally from one language to another?

In nautical terms stop! or cease!?

Myrtaceous tree of mostly Australian genus, such as the blue gum or ironbark, yielding a mecidinal oil from its leaves?

City-state and the largest port in Germany?

A method of voice production by male singers used to vocalise notes higher than their normal range?