Sentence:  Mercer 's Whiteman association brought him into contact with Hoagy Carmichael , whose `` Snowball '' Mercer relyriced as `` Lazybones '' , in which form it became a hit and <WSD>marked</WSD> the real beginning of Mercer 's song writing career . 
Meaning of the word marked with <WSD> tags:  designate as if by a mark