Gymnastics; physical exercise — activities involving bodily movement such as stretches and general calisthenics. Also used with する to mean 'to do exercises'.
毎朝ラジオ体操をしてから出かける。
I do radio calisthenics every morning before going out.
学校では授業の前に軽い体操を行うことがある。
At school, we sometimes do light exercises before class.
体操は柔軟性を高め、怪我を予防するのに役立つ。
Exercises help improve flexibility and prevent injuries.
As an abbreviation, it can mean artistic gymnastics or a gymnastics competition (i.e., the sport of gymnastics, often referring to 体操競技).
オリンピックの体操で日本チームが金メダルを取った。
The Japanese team won a gold medal in Olympic gymnastics.
体操選手は高い柔軟性と集中力が必要だ。
Gymnasts need high flexibility and concentration.
An obsolete usage: it once referred to physical education (PE) classes in school; this meaning is now largely obsolete.
古い学校の文書では『体操』が体育を指す例が見られる。
In old school documents, 'taisō' can be seen referring to physical education.