Set the letter's value in the Refers To box. You can create a value from data in a cell in the worksheet or you can add your own number. By default, Excel puts a reference to the currently selected cell in the box. If this contains your value, keep the default.
Gravely (the adverb) comes from the adjective, which comes from Latin (gravis), where it meant heavy or serious (this is where we get gravity--heaviness). Gravely ill means seriously ill, not soon to be in the grave. (and proof [1]). Bonus tidbit: grave (the noun) comes from words that originally meant to dig then a place dug, as for burial or, a grave. This is the same root as engrave.
ill sickness. a sarcastic way of saying something is good. (used to make fun of wiggers) wigger: man check out ma sick ride yizzo! dude: yeah man! ill sickness! i'll smack you like a red-haired step child at k-mart