Definition for Fifth wheel:

• an extra car wheel and tire for a four- wheel vehicle

Synonyms for Fifth wheel:

• n.

  •artifact (noun)
  • spare,
  • fifth wheel.
  •attribute (noun)
  • Deadwood.
  •somebody or something unnecessary (noun)
  • lagniappe,
  • triviality,
  • spare tire,
  • hanger-on,
  • third wheel,
  • superfluity.

• Other synonyms:

  •n.
  • bearing,
  • car wheel,
  • redundance,
  • redundancy.

Hyponym for Fifth wheel:

• n.

  • artifact
    car wheel, bearing.
  • attribute
    redundancy, redundance.