say vs preface

say and preface both are nouns.

Word	Noun	Adjective	Verb	Adverb
say	Yes	No	Yes	No
preface	Yes	No	Yes	No

As verbs, preface is a hyponym of say; that is, preface is a word with a more specific, narrower meaning than say:

say (noun)	preface (noun)
the chance to speak	a short introductory essay preceding the text of a book

say (verb)	preface (verb)
express in words	furnish with a preface or introduction
report or maintain
speak, pronounce, or utter in a certain way
express a supposition
give instructions to or direct somebody to do something with authority
communicate or express nonverbally
recite or repeat a fixed text
indicate
state as one's opinion or judgement; declare
utter aloud
have or contain a certain wording or form