- 三度空间 sāndùkōngjiān three-dimensional spaceSpace that includes the three dimensions of length, width, and height; also known as [[三维空间|三維空間|san1 wei2 kong1 jian1]]
- 大三度 dàsāndù major thirda musical interval spanning four semitones
- 大小三度 dàxiǎosāndù major and minor thirdmajor and minor third (musical interval)
- 小三度 xiǎosāndù minor thirda musical interval of three semitones
