get a dictionary then
"not lacking or omitting anything; complete."

if a node is not storing the full blockchain. its not FULL
if a node is not fully verifying all of the data it receives its not FULL
if its not offering the full services available its not FULL

its common sense. stuff you can learn by actually understanding what FULL means in any concept/analogy/scenario/product/service

heck go to a masseuse and ask for a full body massage.
if they only rub your toe.. that is not a full body massage