ACROSS
1. <fell> LAY LOW <stayed out of sight>
5. <a bit hungry> PECKISH = C inside P(-i)E + K(-n)ISH
9. BLADE RUNNER outside (-j)OCK = BLOCKADE RUNNER <stealthy merchant ship>
11. <cry> YOWL = OWL after _Y
12. <tax write-off> DEDUCTIBLE = DE DUCTILE outside B
14. AC inside AUDI _O_U_S = AUDACIOUS <reckless>
16. COY PU(-g) = COYPU <large rodent>
17. TANG O = TANGO <dance>
19. <waterproof canvas> TARPAULIN = TAR (UP + NAIL)*
21. <taking back> RECLAIMING = RING outside (ALICE* + M)
23. <part of utterance> WORD = "WHIRRED"
25. (VICE PRESIDENT'S)* = PREDICTIVENESS <telling the truth about upcoming events>
26. CURT ←YES← = CURTSEY <sign of respect>
27. <showed signs of boredom> YAWNED = ←DEN WAY←

DOWN
2. <let> ALLOWED = (ALL WED) outside O
3. <spike> LACE <fabric with many holes>
4. HALE under W = WHALE <strike with violence>
5. <one who was here before> PRECURSOR = P RECURS + OR
6. (SCARCE TUNA)* = CRUSTACEAN <lobster, perhaps>
7. GOBLIN* atop _Y = IGNOBLY <without honour>
8. _H_A_R_ + L + (AD inside EQUINE) = HARLEQUINADE <part of pantomime>
10. (CHICORY PLANT)* = LYCANTHROPIC <taking on lupine qualities>
13. <aerial display> ACROBATICS = ←ORCA← BATS outside _IC_
15. <assessing pupils> OPTOMETRY = OP + TOME TRY
18. N + U + CLEAR = NUCLEAR <sort of power>
20. <gander> LOOK-SEE = LOO ⭯SEEK⭯
22. <construction worker> NAVVY = S→N, SAVVY
24. ←WONK← = KNOW <suspect correctly>