noun

1. A trailer without a front axle and with wheels only at the trailing end, designed to be pulled via a pivoting arrangement which also partially supports its weight.

2. A tractor-trailer or big rig: a semi-trailer plus the truck or tractor pulling it.

Synonyms: 18-wheeler, artic, articulated lorry, big rig, juggernaut, semi, semi-trailer truck, tractor-trailer