Training-wheels
noun, (used with a plural verb)
1.
a pair of small wheels attached one on each side of the rear wheel of a bicycle for stability while one is learning to ride.
Read Also:
- Trainload  
noun, Railroads. 1. the cargo or passenger capacity of a train. 2. a specified minimum number of loaded cars or tons of cargo necessary to secure a special rate (train·load rate)
 - Trainman  
noun, plural trainmen. 1. a member of the crew that operates a railroad train, usually an assistant to the conductor, such as a brakeman or flagman.
 - Trainmaster  
noun 1. a person who has charge of operations over one portion of a railroad.
 - Train of thought  
A succession of connected ideas, a path of reasoning, as in You’ve interrupted my train of thought; now what was I saying? This idiom, which uses train in the sense of “an orderly sequence,” was first recorded in 1651, in philosopher Thomas Hobbes’s Leviathan.
 - Trainshed  
noun 1. (in a railroad station) a shelter completely covering railroad tracks and their adjoining platforms.
 
