Trimester
/traɪˈmɛs.tər/noun
A period of three months, especially one of the three divisions of pregnancy.
Did you know?Trimester derives from the Proto-Indo-European word for 'moon,' connecting human gestation periods to ancient fertility rites synced with lunar phases.
Etymological Timeline
Proto-Indo-European
PIE
*tréyes
“three”
Proto-Indo-European
PIE
*méh₁ns
“moon, month”
8th century BCE
Lat
trēs
“three”
8th century BCE
Lat
mēnsis
“month”
Classical Latin
Lat
trimēstris
“of three months”
16th century
Fr
trimestre
“period of three months”
1821
Eng
trimester
“three-month term (esp. in pregnancy)”