Well, "slithy" means "lithe and slimy." "Lithe" is the same as "active." You see it's like a portmanteau - there are two meanings packed up into one word.
Lewis CarrollIf doubtful whether to end with "yours faithfully," or "yours truly," or "yours most truly," &c. (there are at least a dozen varieties, before you reach "yours affectionately"), refer to your correspondent's last letter, and make your winding-up at least as friendly as his: in fact, even if a shade more friendly, it will do no harm!
Lewis CarrollIt is the privilege of true genius, And especially genius who opens up a new path, To make great mistakes with impunity
Lewis CarrollForbid the day when vivisection shall be practised in every college and school, and when the man of science, looking forth over a world which will then own no other sway than his, shall exult in the thought that he has made of this fair earth, if not a heaven, at least a hell for animals.
Lewis Carroll