I think it may have been 'terrific', though I'm not for absloute certain.
The last word that Charlotte writes is "Humble."
'some pig' 'terrific'
The first word in "Charlotte's Web" is "Where."
Humble
I'm pretty sure it was some pig.
in Maine
White, E.B. Charlotte's Web. Illustrated by Garth Williams. New York: Harpercollins, 1952
The last word written on Charlotte's web was "HUMBLE."
crunchy
She wrote "Some Pig"
1952
Charlotte the spider uses her silk thread to write words in her web. She spins the words using her silk, creating messages that captivate and amaze those who see them.