Across

• 1. In retrospect, introductory science communication is surely a book of fundamentals. (6)
• 4. Way out found in empty robe. (5)
• 8. I meant to dance around and clean up. (13)
• 9. Ages during premature onset... (4)
• 10. Stand capably and tolerably? (8)
• 12. Rip off Cher song; "Hat Pop!" (11)
• 14. Difficult choices amid elms being pulped. (8)
• 15. "Ours is fresh and acidic" (4)
• 17. Tryouts; I flail about provocatively. (13)
• 18. Primarily yelled of gymnastics; "I can't be related to yogis!" (5)
• 19. Protein for gen-z scratching head... "why me?" (6)

Down

• 1. Harass an animal? (6)
• 2. Chloe spending liberally for more food? (13)
• 3. Walking stick is able to finally decompose. (4)
• 4. Liar backtracked on Dora's crude line? (8)
• 5. Album I sung you was terrible... without a doubt... (13)
• 6. Yemen mobilised combatant. (5)
• 7. Fat rat's crew manoeuvred boats (11)
• 11. Smelly cat Moira put out. (8)
• 13. Pattern e.g. lyra removed (6)
• 14. Silly fad makes a come back with fifty banks? (5)
• 16. Quaff feathers?! (4)