proem
Concise Oxford English Dictionary © 2008 Oxford University Press:
proem /ˈprəʊɪm/
▶noun formal a preface or preamble to a book or speech.
– derivatives
proemial /-ˈiːmɪəl/ adjective.
proemial /-ˈiːmɪəl/ adjective.
– origin ME: from OFr. proeme, via L. from Gk prooimion ‘prelude’, from pro ‘before’ + oimē ‘song’.
'proem' also found in these Oxford entries:

