Theme: May I have a word with you? - Words that are a???? are split into two words and clued as such.
20. One hospital celebration? : AWARD CEREMONY. A WARD CEREMONY (Ward - section of a hospital)
25. One mug from the boxing ring? : ABOUT FACE. (military command) A bout face; a face after a bout in boxing.
46. One news magazine managing editor? : AHEAD OF TIME. A head of Time(Time magazine)
52. One adorable romantic threesome? : ACUTE TRIANGLE. (triangle that has all angles less than 90°) A cute triangle.
Argyle here but no reveal. The puzzle has mirror crossword symmetry. Many proper names. I added a few songs to ease the pain.
1. Nothing, in Nogales : NADA but here's something...I'm not sure what.
5. A-list invitee : CELEB
10. Inhale in awe : [GASP!]
14. "The Big Country" Oscar winner Ives : BURL. Here is a clip from the movie. Clip(2:41)
15. Hertz competitor : ALAMO
16. Germany's von Bismarck : OTTO
17. Study at the last minute : CRAM
18. Decorated anew : REDID
19. Grown-up tadpole : TOAD
23. The blahs : ENNUI
24. Radon and ozone : GASES
29. Joe of "Casino" : PESCI. Pesci played Nicholas "Nicky" Santoro.
32. [Not my typo] : (SIC)
33. Ethan of "Before Midnight" : HAWKE
37. Sound system component : AMP
38. "Honest!" : "NOT A LIE!" Sure. 40D. "Honest?" : "IS THAT SO?"
41. Breathable mixture : AIR
42. "Count on it" lawnmower brand : TORO
44. Fast-spreading Internet phenomena : MEMES
45. Michelin rating unit : STAR
49. Without question : BY FAR
50. Store posting : HOURS
56. Long-distance swimmer Diana : NYAD. When she was 64, she swam from Cuba to Florida, the first person confirmed to have done so.
57. Crime scene clue exposed by dusting : PRINT
58. Hereditary code carrier : GENE
60. Table tennis video game : PONG. Do you remember?
61. Cozumel cash : PESOs. Was that where the ill-fated cruise was headed a few years back?
62. "__ but not least ... " : LAST
63. Trick : RUSE
64. Look after : SEE TO
65. Barely managed, with "out" : EKED
1. "Parks and Recreation" network : NBC
2. Heavenly glows : AURAE
3. Written (up), as a contract : DRAWN
4. Annually updated reference : ALMANAC. Did any almanac predict this winter?
5. Pulse-boosting exercise, for short : CARDIO
6. Utility measured in kilowatt hrs. : ELEC.
7. Fill with cargo : LADE
8. Qatari bigwig : EMIR
9. Hispanic convenience store : BODEGA
10. Set sail : GO TO SEA
11. Make reparations : ATONE
12. Hangs around : STAYS
13. Sci-fi escape craft : POD
21. Apply before cooking, as spice to meat : RUB IN
22. Papier-__ : MÂCHÉ
26. Spanish pronoun : USTED. (you)
27. Words of grande affetto : TI AMO. Italian for "I love you".
28. Bass staff symbol : F CLEF
29. On-the-back praise : PAT
30. Expressive rock genre : EMO
31. "Contents under pressure" containers : SPRAY CANS. Do not incinerate.
34. Plumbing problem : WATER LEAK
35. Sorento automaker : KIA
36. Throw wide of the cutoff man, say : ERR. (baseball)
39. Dr. Eric Foreman portrayer on "House" : OMAR EPPS. Full name today.
43. G-rated cry of dismay : "OH, FUDGE!"
45. Sneak across the border : SMUGGLE
47. Nosh : EAT
48. Electrified particle : ION
49. Louisiana wetland : BAYOU
51. Hearing, for one : SENSE
53. It has bark, but no bite : TREE
54. Get out of bed : RISE
55. Playing a fourth NHL period : IN OT. (overtime)
56. Network home to "A Prairie Home Companion" : NPR. (National Public Radio)
59. Takeoff approx. : ETD. (Estimated Time of Departure)