gudgeon

Concise Oxford English Dictionary © 2008 Oxford University Press:
gudgeon1 /ˈgʌdʒ(ə)n/

▶noun

• 1 a small freshwater fish often used as bait by anglers. [Gobio gobio.]

• 2 archaic a credulous person.

– origin ME: from OFr. goujon, from L. gobio(n-), from gobius ‘goby’.

Concise Oxford English Dictionary © 2008 Oxford University Press:
gudgeon2 /ˈgʌdʒ(ə)n/

▶noun

• 1 a pivot or spindle on which a bell or other object swings or rotates.

• 2 the tubular part of a hinge into which the pin fits.

• 3 a socket at the stern of a boat, into which the rudder is fitted.

• 4 a pin holding two blocks of stone together.

– origin ME: from OFr. goujon, dimin. of gouge (see gouge).