'postpaschal' originates from Latin elements: the prefix 'post-' (Latin) meaning 'after' and 'paschalis' (Late Latin) meaning 'of or relating to Passover/Easter'.

'paschalis' came from Late Latin 'paschalis', from Greek 'Pascha', ultimately from Hebrew 'Pesach' meaning 'Passover'; English formed the compound 'post-' + 'paschal' to create 'postpaschal'.

Initially used to indicate timing after the Jewish Passover, in Christian usage it came to mean 'after Easter' (the Christian Paschal feast) and specifically refers to the liturgical period after Easter.