That > [So that]

5 Therein is eaten out a hollow cave,

hollow > hollow; insincere, false, hungry

6 That seems rough mason's hand with engines keen

engines > tools; machines keen > sharp

7 Had long while laboured, it to engrave:

engrave > sculpture; hence: carve out

8 There was his won, nor living wight was seen,

won > dwelling-place wight > creature

9 Save one old nymph, hight Panope, to keep it clean.