As adjectives the difference between snippiest and slippiest
is that snippiest is (snippy) while slippiest is (slippy).
snippiest
English
Adjective
(head)
(snippy)
snippy
English
Adjective
(er)
fragmentary; snipped.
irritable; impatient; short-tempered.
slippiest
English
Adjective
(head)
(slippy)
slippy
English
Adjective
(
er)
Slippery.
* 1922 , (James Joyce), Chapter 13
- It was darker now and there were stones and bits of wood on the strand and slippy seaweed.
(dialect, dated) Spry, nimble.
*1913 ,
*:Well, come on then, let's look slippy .