Anu's Word: spoonerism
MEANING: noun: The transposition of (usually) the initial sounds of words producing a humorous result. For example:
"It is now kisstomary to cuss the bride." (Spooner while officiating at a wedding)
"Is the bean dizzy?" (Spooner questioning the secretary of his dean)
ETYMOLOGY: After William Archibald Spooner (1844-1930), clergyman and educator, who was prone to this. Earliest documented use: 1900.

change N to K

SPOOKERISM: When a spooner-prone spook says "phoo" instead of "boo" and then wonders why no one is afraid.