What does the term 'fathers' mean in Hebrews chapter 1 verse 1?

Hebrews 1:1 - God, who at various times and in various ways spoke in time past to the fathers by the prophets,[NKJV]

In this instance, "fathers" is a reference to the Old Testament patriarchs; those to whom God spoke "in time past." Men such as Abraham, Isaac, David, etc.