Theme: Pedestrian Span - the word FOOT bridges the theme entries.
17A. *Grocery store: FOOD MARKET
28A. *Vessel for a cheesy dip: FONDUE POT
37A. *Ballroom dance that's also a phonetic alphabet "F": FOX TROT
44A. *All-terrain high shoe: FIELD BOOT
56A. Stream crossing for pedestrians ... and what is literally provided by the interior letters in the answers to starred clues: FOOT BRIDGE
Argyle here. There are circles but not really needed.
Across:
1. Cried on cue, say: ACTED
6. Nimble-fingered: DEFT
10. Auntie on Broadway: MAME. Before the musical.
14. Africa's Sierra __: LEONE
15. Butterlike topping: OLEO
16. Beatnik's "Understood": "I DIG"
19. Join the chorus: SING
20. Like the chains in a chain necklace: LINKED
21. Camp beds: BUNKS
22. Swear (to): ATTEST
25. Pair in a dinghy: OARS
27. Employee's reward: RAISE
33. Cone-dropping trees: FIRS
34. Recycling receptacle: BIN
35. Maps within maps: INSETS
36. Therapists' org.: APA. (American Psychological Association)
39. Shatner's "__War": TEK. William Shatner
40. Cash in, as coupons: REDEEM
42. "I __ only kidding": WAS. text JK
43. Shoulder muscle, for short: DELT
46. Sandburg and Sagan: CARLS. The poet and the astronomer.
47. Highest in quality: BEST
48. Gives a thumbs-up: SAYS OK
49. Wrinkle-removing injection: BOTOX
52. Acquires, as debts: INCURS
55. State firmly: AVOW
60. Filet mignon order: RARE
61. World power initials until 1991: USSR. (Union of Soviet Socialist Republics)
62. How contracts are signed: IN INK
63. Iditarod vehicle: SLED
64. Fishing rod partner: REEL
65. Occur as a result: ENSUE
Down:
1. 1980s TV ET: ALF. Gordon Shumway from the planet Melmac.
2. Corporate VIP: CEO. (chief executive officer)
3. Also: TOO
4. Tiresomely long: ENDLESS
5. Downfall: DEMISE
6. Nerdy sort: DORK
7. Sommer of cinema: ELKE. For Splynter.
8. Get nourishment from: FEED ON
9. Trike rider: TOT
10. Applies incorrectly: MISUSES
11. Score after deuce: AD IN. (tennis) The server's advantage.
12. Ermine cousin: MINK
13. They're often scrambled: EGGS
18. Tiny farm denizen: ANT
21. Main impact: BRUNT
22. Repetitive barking: [ARF! ARF!] and on the opposite side of the grid, 32. "You should be ashamed!": "TSK!, TSK!"
23. Taiwan's capital: TAIPEI
24. Rabble-rousing outburst: TIRADE
26. "Hasta la vista": "ADIOS"
28. Predicament: FIX
29. Quarterback's "Snap the ball at the second 'hut'": "ON TWO"
30. Fizzles (out): PETERS
31. Verdi opera with Desdemona: OTELLO
34. Lays an egg on stage: BOMBS
37. UPS alternative: FEDEX
38. Word before or after pack: RAT
41. Nudged sharply: ELBOWED
43. Best Western competitor: DAYS INN
45. Lazy: OTIOSE. Straight from Latin.
46. Underwood who performs the "Sunday Night Football" opening: CARRIE
48. Classroom stand-in: SUB. CSO's
49. Happy hour places: BARS
50. Mirror shape: OVAL
51. Ran like mad: TORE
53. Smoke detector?: NOSE
54. PC corner key: CTRL. (control)
56. Calico coat: FUR
57. Put down: DIS. (disrespect or disparage)
58. Oxlike antelope: GNU
59. Barely manage, with "out": EKE
Argyle
Argyle
Note from C.C.