1) Automotive styling feature 2) Covering for a river bed 3) Railroad train 4) Sleek train 5) Train 
A streamliner is a vehicle incorporating streamlining in a shape providing reduced air resistance. The term is applied to high-speed railway trainsets of the 1930s to 1950s, and to their successor `bullet trains`. Less commonly, the term is applied to fully faired recumbent bicycles. As part of the Streamline Moderne trend, the term was applied .....
[n] - a streamlined train
noun a streamlined train
something that is streamlined, esp. a locomotive or passenger train.