bob·sled 
(bŏbslĕd′)
(bŏbslĕd′)n.
1. A long metal racing sled with a steering mechanism that controls the front runners and a hand brake, usually raced down a curving ice-covered course by crews of two or four riders.
2.
a. A long sled made of two shorter sleds joined in tandem.
b. Either of these two smaller sleds.
intr.v. bob·sled·ded, bob·sled·ding, bob·sleds
To ride or race in a bobsled.
[BOB2 + SLED.]
bobsled·der n.
bobsled