William Sinclair Boyd (of Sinclair & Boyd), Ravenscroft House, Bloomfield is listed in the Belfast And Province Of Ulster Directory 1884. It is marked on the 3rd edition OS 6" map (c. 1900) and was situated roughly where Hillcrest Gardens is today. It is likely Ravenscroft Avenue and Ravenscroft Street take their names from this house, even though it was situated approx. half a mile away.
The reason for the naming of the house are unclear. There are examples of Ravenscroft as a place-name in northern England, though it does not survive as a town or village. It was the name of a house in Huyton near Liverpool, for example. It also occurs as a surname, originally from Cheshire, pointing to a lost medieval place-name near Middlewich.
"Resolved - That the name Ravenscroft Gardens be approved for a new street on ground off Bloomfield Road, the property of Mr. R. S. Boyd". (13th February 1934).