In an illusion, the importance lies in what a word --represents, sounds like, states, rhymes with

Represents

Explanation:

i have heard the mermaids singing, each to each.

i do not think they will sing to me

voracity is the noun corresponding to the adjective voracious, which means (1) eager to consume a great amount of food, or (2) marked by an insatiable appetite. veracity is far more common than the rare voracity, so the latter is sometimes used in place of the former.