"Semi-trailer" Natural Recordings by Native Speakers
A semi-trailer, also known as a semi, semi-truck, or eighteen-wheeler, is a large articulated vehicle used for transporting goods or materials over land. It consists of a combination of a tractor unit (which pulls the trailer) attached to a semi-trailer unit, hence the name. The trailer is not connected by a fixed axle to the tractor and is designed to be easily detachable.
Holding or showing a moderate level of skill or training in a particular area, but not to a high or professional standard.
Halfway; partially.<br><br>Example: "The movie was a semi-success" (not entirely successful, but somewhat successful).