The only link on Google is to this Wikipedia page on a “Poetic Retelling of Genesis”. I gather Lēoþ means “song”, but there is no definition of the other word. Does is just say “In the beginning” or something?
BTW, where did that Poetic Retelling come from? Side note.
The word Ȝecyndbēc is defined by the Dictionary of Old English (under the spelling gecyndboc) as:
Genesis, literally understood as the book of creation or begetting
It is made of two words: bec/boc (book) and Ȝecynd/gecynd, the latter of which has no modern equivalent but is a combination itself of the prefix ge-/ȝe- (also has no modern English equivalent) and kind. In Old English the word gecynd had several different related meanings (according to the OED) including family, gender/sex, genitals, and progeny.
Actually “Genesis” was also used in Old English. Ælfric writes:
seo boc ys gehaten Genesis, þæt ys gecyndboc, for þam þe heo ys firmest boca & spricþ be ælcum gecinde.
“The book is named Genesis, that is gecyndboc…”