Wiktionary
n. (context UK English) A vehicle from which ice cream is sold at the roadside, mostly to children.
Wikipedia
An ice cream van ( British) or ice cream truck ( American) is a commercial vehicle that serves as a mobile retail outlet for ice cream, usually during the summer. Ice cream vans are often seen parked at public events, or near parks, beaches, or other areas where people congregate. Ice cream vans often travel near where children play — outside schools, in residential areas, or in other locations. They usually stop briefly before moving on to the next street.
Ice cream vans are often brightly decorated and carry images of ice cream, or some other adornment, such as cartoon characters. They may have painted-on notices, which can serve a commercial purpose ("Stop me and buy one!") or a more serious one ("Don't Skid on a Kid!") - serving as a warning to passing motorists that children may run out into the road at the sight of the van, or appear without warning from behind it. Along the sides, a large sliding window acts as a serving hatch, and this is often covered with small pictures of the available products, with their associated prices. A distinctive feature of ice cream vans is their melodic chimes, and often these take the form of a famous and recognizable tune, usually in the USA " The Mister Softee Jingle", " Turkey in the Straw", " Do Your Ears Hang Low?, " Pop Goes The Weasel", " The Entertainer", " Music Box Dancer", " Home on the Range", " It's a Small World", a tune from the opera Le devin du village more commonly known as the American folk song "Go Tell Aunt Rhody", "The Picnic" (a Japanese children's song usually played with a recording of a woman saying 'hello' at the end of the song on ice cream trucks), or " Camptown Races"; or, in Australia, New Zealand and the United Kingdom, " Greensleeves", " It's Now Or Never (song)", " Whistle While You Work" in Crewe and Nantwich, " You Are My Sunshine" in Vale Royal, " Teddy Bears' Picnic" in Sheffield, and " Match of the Day" in other places. In some places in the US, ice cream trucks play the song "Ice Cream" by Andre Nickatina (essentially just Turkey in the Straw with bass).
Most ice cream vans tend to sell both pre-manufactured ice pops in wrappers, and soft serve ice cream from a machine, served in a cone, and often with a chocolate flake (in Britain) or a sugary syrup flavoured with, for example, strawberry. Soft serve ice cream is served topped with sprinkles for a slight extra charge. While franchises or chains are rare within the ice cream truck community (most trucks are independently owned/run), some do exist.
In some locations, ice cream van operators have diversified to fill gaps in the market for soft drinks, using their capacity for refrigerated storage to sell chilled cans and bottles.
Early ice cream vans carried simple ice cream, during a time when most families did not own a freezer. As freezers became more commonplace, ice cream vans moved towards selling novelty ice cream items, such as bars and popsicles. Early vans used relatively primitive techniques: their refrigeration was ensured by large blocks of dry ice so the engine was always turned off when the van was stopped for sales. The chimes were operated by a hand driven crank or a take-off from the engine, so they were not heard as often. Modern chimes are always electrically operated and amplified.