When did the word sniggering become snickering?
Snickering is the older word, according to Merriam-Webster, but not by much:
Snicker: First Known Use: 1694Appears to me that the era's multiple phonetic spellings are to blame for the small shade of difference. Sniggering seems to me to connote a tiny bit more suppressed form of laughing than snickering.
Snigger: First Known Use: circa 1706
I would think, with today's hysteria over triggering, that sniggering would excite the same inappropriate reaction as "niggardly", etc. Frankly, I'm surprised that "triggering" still makes the cut.