Used other than figuratively or idiomatically: see first, night.
The first night after marriage.
The first public performance of a play or other show, normally assumed to be held in the evening.
The act of initiating, or the process of being initiated or introduced
The first step of transcription or of transduction.
The form or ceremony by which a person is introduced into any society; mode of entrance into an organized body; especially, the rite of admission into a secret society or order.