Theme: Unfettered - Three synonyms that while they may not be synonyms of each other or how they are used in their phrase, are synonyms of the unifier.
17A. Quits worrying : RESTS EASY. Easy in the phrase is an adverb but as a synonym of loose, that something or someone is permissive, is an adjective.
27A. Like 56 minutes of each hour of The Masters telecast : COMMERCIAL-FREE. The phrase use is as unobstructed but as a synonym of loose, free is unrestrained.
47A. "Get off my back!" : "CUT ME SOME SLACK!". Here slack is part of an idiom, to give someone a break. As a synonym of loose, slack is the antonym of taut.
62A. Unfinished business, or, in a way, what 17-, 27- and 47-Across have in common : LOOSE ENDS
Argyle here. This softball turned into a hardball when I tried to write it up. Thanks a lot, Marti. I hope I got it right. Good solid corners, the way Rich likes them.
Across:
1. Ho-hum time : DRAG. No drag here.
5. Ship's command post : HELM
9. Zip preceder : STATE
14. Really-really : OH SO. Superlatively qualitative. and 25D. Chop-chop : PRONTO
15. Verdi's "Celeste Aida," e.g. : ARIA
16. Hypothesize : POSIT
19. Oohed and __ : AAHed
20. "Luncheon on the Grass" painter : MANET. You know, the two guys and the naked chick.
21. Law firm bigwigs : PARTNERS
23. Group with many golden agers : AARP. If you don't know AARP, well, bless you son.
26. Failed firecracker : DUD
34. Federal web address ending : .GOV
35. Office betting groups : POOLS
37. TV's talking horse : MR. ED
39. Drum kit drum : SNARE
41. "Want the light __ off?" : ON OR
42. "Stick Up for Yourself" nasal spray : AFRIN
44. Glittery topper : TIARA
46. Molecule with a + charge, e.g. : ION
50. Mischief-maker : IMP
51. Hose fillers? : LEGS. I'm leaving this for Splynter.
52. Wide-awake : OPEN-EYED
57. Wanted poster word : ALIAS
61. Longish skirts : MIDIs
65. Temporarily unavailable : [IN USE]
66. Sask. neighbor : ALTA. (Saskatchewan/Alberta, Canada)
67. Macro or micro subj. : ECON.. Could be ECOL?
68. Help desk staffers, usually : TECHs
69. Hornet's home : NEST
70. Tebow throw, say : PASS. Still chuckle at New York Jest(from a past puzzle).
Down:
1. Quarter of a quad, perhaps : DORM. Quadrangle/Dormitory
2. Perlman of "Cheers" : RHEA Here is a classic clip.(I can't stop laughing) And seasonal, too.
3. Part of YMCA: Abbr. : ASSN.
4. Pep rally cry : "GO TEAM!"
5. Possess, in the Hebrides : HAE
6. Christian __ : ERA
7. Speech impediment : LISP
8. Honduras native : MAYA
9. Patty turner : SPATULA
10. How a pendulum swings : TO AND FRO
11. Tennis great Arthur : ASHE
12. Row at Wrigley : TIER. More alliteration.
13. LAX guesstimates : ETD's. Or any airport.
18. Email doesn't require one : STAMP
22. Nutritional abbr. : RDA. (recommended daily allowance)
24. 1920s-'30s Flying Clouds, e.g. : REOs. Early luxury cars from Oldsmobile.
27. Greek vacation isle : CORFU. A Greek island in the Ionian Sea.
28. For all to see : OVERT
29. Insurance case : CLAIM
30. Knesset country : ISRAEL. Knesset - The unicameral parliament of Israel [Hebrew, literally: gathering] Unicameral - consisting of a single chamber, as a legislative assembly.
31. Written in mystical letters : RUNIC
32. Kindle download : E-BOOK
33. Deservedly get : EARN
34. Former car-financing org. : GMAC. (General Motors Acceptance Corporation)
38. Dwindle : DIMINISH
40. Hebrides tongue : ERSE. Map. Home to Talisker Scotch.
43. Archrivals : NEMESES. Super heros seem to attract them.
45. Aquarium accumulation : ALGAE. Shouldn't there be little critters in there eating that stuff.
48. One seeking intelligence : SPY
49. In dreamland : ASLEEP. Where I should be.
52. Leave out : OMIT
53. "Ponderosa" tree : PINE
54. PTA's focus : EDUC.. Locally, it is PTSA, Parent-Teacher-Student Association. Is that what your school has?
55. Lust for life : ELAN
56. Charitable distribution : DOLE. What to do with the contributions.
58. Machu Picchu resident : INCA
59. Fusses : ADOs
60. Federal IDs : SSN's
63. Extra NHL periods : OT's
64. Did nothing : SAT
Argyle