My wife and I went to San Francisco on vacation last month. One of the big attractions there is Fisherman's Wharf. We got into a discussion about what exactly a wharf was, and that also tripped my etymology switch.
I said I thought a wharf was the area on the shore that the piers were attached to, she said she thought it was the actual piers. She was right, according to the OED:
- 1. A substantial structure of timber, stone, etc., built along the water's edge, so that ships may lie alongside for loading and unloading. Often with prefixed nouns, as fish-wharf, gun-wharf.
- 2a. An embankment, mole, or dam. Obsolete.
- 2b. A terrace or raised platform. Obsolete.
- 2c. The bank of a river (Obsolete); also, a gravel or sandbank.
- 2d. A large raft. Obsolete, rare.
- 2e. A place raised or otherwise marked out on which stuff is deposited for subsequent removal to another place.
So a pier is a wharf, though not all wharfs are piers.
Wharf comes from the "late Old English hwearf (compare to earlier poetical comparative merehwearf, meaning sea-shore), corresponding to Middle Low German warf, werf, meaning mole, dam, wharf, raised site protected from flooding (Late German warf), whence Early Frisian warf, werf, Dutch werf, meaning shipyard, German werf, meaning wharf, pier, werft, meaning dockyard."