1. Islam. Zeno is the founder of Stoicism, and Muhammad is the founder of Islam.
2. 61. Babe Ruth broke the record for the number of home runs hit in a season by hitting 60 home runs, & Maris broke the record by hitting 61 home runs.
3. stealthy. Tertiary and third are synonyms, as are feline and stealthy.
4. Tarzan. Raymond created Flash Gordon, and Burroughs created Tarzan.
5. trickery. Chic and fashionable are synonyms, as are chicanery and trickery.
6. obduracy. Fortitude and endurance are synonyms, as are intransigence and obduracy.
7. Franklin. Gutenberg invented movable type, and Franklin invented the lightning rod.
8. virtue. The analogy uses the beginning and ending parts of two well known sayings: "curiosity killed the cat," and "patience is a virtue."
9. Challenger. Greenhouse and photoelectric are words that are often followed by "effect," and Titanic and Challenger are two words that are often followed by "disaster."
10. Arthur. Sarah was married to Abraham, and Guinevere was married to Arthur.
11. wealthy. Corpulent and obese are synonyms, as are opulent and wealthy.
12. capon. A castrated man is a eunuch, and a castrated rooster is a capon.
13. Schwartz. In the movie Star Wars, the Force was important, and used in sayings such as "may the Force be with you." In the movie Space Balls, a parody of Star Wars, the word "Schwartz" was used instead of "Force."
14. rationalism. Stygian and celestial are antonyms, and empiricism and rationalism are two philosophical schools of thought that are opposed to one another.
15. monkshood. Aconite is known as wolfsbane and also as monkshood.
16. kindred. All of the other words are synonyms and/or very closely related.
17. crow. All of the other words are synonyms of the word "black."
18. Quayle. The other names are of men who held the position of President of the United States.
19. Tageozoic. The three great eras are: the Paleozoic (ancient life), the Mesozoic (middle life), and the Cenozoic (recent life). Tageozoic is a fictional word that I made up.
20. Maya. The other names are North American tribes.
21. volt. The other words are units of length.
22. think. The other words are or can be nouns, while think is only a verb.
23. frequency. This was a tough one! If the word "heavy" is placed before all of the words except frequency, a new term is created (i.e. heavy water, heavy metal, heavy chain, and heavy hydrogen).