Preffix non- means:
not
Suffix -free means:
not containing the (usually bad) thing mentioned
Prefix un- means:
the opposite
not dairy
nondairy
not fat
nonfat
not fiction
nonfiction
free of smoke
smoke-free
free of sugar
sugar-free
free of salt
salt-free
opposite of "safe"
unsafe
opposite of "true"
untrue
opposite of "healthy"
unhealthy
