- 三合一 sānhéyī three-in-onethree-in-one; triple
- 天人合一 tiānrénhéyī oneness of heaven and humanityThe philosophical theory that humanity is an integral part of nature or the cosmos; the state of being in harmony with the universe.
- 知行合一 zhīxínghéyī unity of knowledge and actionA philosophical concept established by the Ming Dynasty scholar [[王守仁|王守仁|wang2 shou3 ren2]], which argues that knowing and doing are inseparable; to know but not to act is equivalent to not truly knowing.
- 二合一 èrhéyī two-in-onetwo things combined into one; 2-in-1
- 三合一疫苗 sānhéyīyìmiáo DTP vaccinationDTP vaccination; a combined vaccine against diphtheria, tetanus, and pertussis
- 政教合一 zhèngjiàohéyī theocracypolitical system where government and religion are unified; the union of church and state or Caesaropapism
- 文武合一 wénwǔhéyī possessing both civil and military talentsDescribing a person who is proficient in both scholarly and martial pursuits; having both literary and military skills
