training wheel

Prince Carlos, Duke of Parma, riding a bicycle with training wheels (sense 3) in 1973.

A training wheel (sense 3, foreground) on a bicycle.

From training (“relating to the moving of a firearm laterally so that it points in a different direction; relating to imparting and acquiring skills”) +‎ wheel.^[1][2]

• (Received Pronunciation) IPA^(key): /ˈtɹeɪnɪŋ wiːl/

• Audio (Southern England):

  (file)

• (General American) IPA^(key): /ˈtreɪnɪŋ ˌ(h)wil/
• Hyphenation: train‧ing wheel

training wheel (plural training wheels)

1. (military, historical) A wheel forming part of the machinery of a cannon or a similar firearm which is turned to train or aim the weapon at a target.
2. (rail transport, archaic) Synonym of trailing wheel (“on a steam locomotive, an unpowered wheel or axle located behind the driving wheels”)
3. (chiefly Canada, US and in the plural, cycling) One of a pair of small wheels, each attached to one side of a bicycle's rear wheel to provide support for new riders.

   Synonyms: stabiliser, stabilizer

• training wheels (“anything designed to make something easier for a novice”)

• training wheels on Wikipedia.Wikipedia