a rough track or pathway, especially through the countryside, forest, or mountains, that people or animals follow.
The hikers followed the narrow trail up the mountain to reach the lake.
A well-marked trail runs behind the campsite and loops back after three miles.
✦ From Middle English traille, from Old French trailler “to tow, drag,” from Vulgar Latin *tragulare, frequentative of Latin trahere “to pull.”
a series of signs, marks, smells, or clues that someone or something leaves behind as it moves.
The detectives followed a muddy trail of footprints to the back door.
The ants formed a living trail from the sugar bowl to their nest.
a long thin line or stream left behind by a moving object, such as smoke, vapor, or light.
The plane left a white trail of vapor across the clear blue sky.
A glowing trail of sparks followed the firework as it arced overhead.
to pull or let something hang so that it drags along the ground behind you.
She trailed her scarf in the snow without noticing.
The little boy trailed his toy truck by a string across the yard.
to move slowly or fall behind others because you are tired or slower.
The children trailed behind their teacher during the museum tour.
I started to trail after the fourth mile of the race.
to be behind an opponent in points, votes, or progress.
Our team trailed by two goals at halftime.
The candidate still trails her rival in the latest polls.
a record or sequence of evidence that shows what someone has done or how something happened, especially in documents or data.
The email trail revealed who had approved the payment.
Hackers tried to erase their digital trail, but the security team found it.
to grow or hang downward or over a surface in a loose line.
Ivy trailed down the old brick wall.
Her long hair trailed over her shoulders.
to secretly follow someone in order to find out where they go or what they do.
The private detective trailed the suspect for three days.
Police cars trailed the stolen van along the highway.
a vehicle or wheeled platform that is pulled by a car, truck, or tractor to move goods, animals, or equipment
The farmer loaded hay bales onto the trailer behind his tractor.
We attached a small trailer to the car for our camping trip.
✦ From trail + -er, first recorded in the late 19th century for wagons pulled behind motor vehicles
a large vehicle or structure on wheels, often placed in a park, that people use as a permanent or semi-permanent home
They bought a trailer in Florida and spend winters there.
The storm damaged several trailers in the park.
✦ Extension of the vehicle sense; U.S. usage from the 1930s when house trailers became popular for affordable housing
extra data placed at the end of a computer file or message that carries control information or marks where it finishes
The network packet includes a header and a trailer for error checking.
Removing the corrupted trailer fixed the video file.
✦ Adopted by computer engineers by analogy with the section that comes after (trails) the main data block
