What's a "snigger"? Must be a "snicker" on drugs.
Snigger has been a perfectly legitimate word since before you were born. See verse III, part two of "The Highwayman" by Alfred Noyes for an example of usage.
http://www.cs.pdx.edu/~trent/ochs/lyrics/highwayman-orig.html
When I was in school this was one of the poems we read in about the 6 th grade.