IPA: //prəˈθæl.əˌmaɪ.ən//
KK: /proʊˈθæləmɪən/
A type of song that is sung to celebrate a wedding or marriage.
The couple chose a beautiful prothalamion to be sung at their wedding ceremony.
Prothalamion is derived from the Greek prefix "pro-" (meaning before) and "thalamos" (meaning chamber or bridal chamber). The term originally referred to a song or poem sung in celebration before a wedding, thus combining the ideas of 'before' and 'bridal chamber'.
Think of 'pro-' meaning 'before' and 'thalamos' referring to a 'bridal chamber' — this helps you remember that a prothalamion is a celebration that happens before a wedding.