Take the previous word and add another word after it. Makes sense? No, not really, I hear you say but...
THE LAST TWO OR THREE LETTERS OF THE EXISTING WORD PLUS THE FIRST TWO OR THREE LETTERS OF THE NEW WORD MUST ALSO MAKE A WORD THEMSELVES.
So...
GrandMA-KErosene
keroseNE-VERsatile
Want to try?
Canon-
EDIT:
In the event that a word using the last two or three letters cannot be created, A genuine place name such as a town, village, district, etc, may be substituted.
ACRONYMS may NOT be used unless they are accepted by the OED as in everyday use, such as SCUBA
"Those who cannot remember the past are condemned to repeat it." George Santayana