Trimester refers to a term of three (3) months; a term often used to describe stages of pregnancies that usually consist of three (3) trimesters.

In the psychology context, a trimester refers to a period of three months. The term "trimester" is often used in the context of pregnancy, as pregnancy is typically divided into three trimesters of approximately three months each.

Examples of trimester in the psychology context include:

  • The first trimester of pregnancy, which is typically the first 12 weeks and is a time of rapid development and growth for the fetus
  • The second trimester of pregnancy, which is typically the second 12 weeks and is a time of continued fetal development and growth
  • The third trimester of pregnancy, which is typically the final 12 weeks and is a time of further fetal development and preparation for birth

Trimesters may also be used in other contexts, such as in the context of academic programs or treatment programs that are divided into three-month periods. Psychologists and other mental health professionals may refer to trimesters in order to track the progress or development of an individual over time.