A woman's abbreviated two-piece bathing suit; SYN. two-piece.
Two-piece version of the women's swimsuit, introduced 1946 in France. Early designs were heavily decorated with frills and artificial flowers. By the 1950s bikinis were popular in France, but they did not become acceptable beachwear until the early 1960s in Britain and around 1965 in the US. In the 1970s a briefer version of the bikini was introduced; the shapes and designs continue to change with fashion trends.

The name derives from the Bikini atoll in the Marshall Islands, W Pacific, where US atomic bomb test explosions were carried out 1946. The bikini was supposed to make a similarly explosive impact.
Atoll in the Marshall Islands, W Pacific, where the US carried out 23 atomic- and hydrogen-bomb tests (some underwater) 1946–58.
The islanders were relocated by the US before 1946. Some returned after Bikini was declared safe for habitation 1969, but they were again removed in the late 1970s because of continuing harmful levels of radiation. In 1990 a US plan was announced to remove radioactive topsoil, allowing 800 islanders to return home.