Unfamiliar Words and Their Meanings:
1. Ephemeral (adjective): Lasting for a very short time; fleeting.
2. Serendipitous (adjective): Occurring or discovered by chance in a happy or beneficial way.
3. Ubiquitous (adjective): Present, appearing, or found everywhere.
4. Quixotic (adjective): Extravagantly idealistic; unrealistic and impractical.
5. Mellifluous (adjective): Sweet or musical; pleasing to the ear.
6. Somnolent (adjective): Sleepy; drowsy.
7. Pernicious (adjective): Having a harmful effect, especially in a gradual or subtle way.
8. Sanguine (adjective): Optimistic or positive, especially in a way that is cheerful or confident.
9. Erudite (adjective): Having or showing great knowledge or learning.
10. Precipitate (verb): To cause (something) to happen suddenly or unexpectedly.
11. Inimical (adjective): Hostile or unfriendly.
12. Petrichor (noun): The pleasant, earthy scent after rain.
13. Cacography (noun): Bad handwriting.
14. Petrichor (noun): The pleasant, earthy scent after rain.
15. Schadenfreude (noun): Pleasure derived from the misfortunes of others.
16. Halcyon (adjective): Denoting a period of time in the past that was idyllically happy and peaceful.
17. Effervescent (adjective): Lively and enthusiastic; bubbly.
18. Laconic (adjective): Using very few words; concise.
19. Ephemeral (adjective): Lasting for a very short time; fleeting.
20. Loquacious (adjective): Tending to talk a great deal; talkative.
This is just a small sample of unfamiliar words. There are countless other words out there waiting to be discovered!