1. Place for a pencil sharpener → DESK
5. Argentine plain → PAMPA
10. Prayer leader → IMAM
14. Droves → ATON
15. Disney princess who longs to be "part of that world" → ARIEL
16. Come to → WAKE
17. Either acting sibling Andrew or Elisabeth → SHUE
18. What pulls out all the stops? → DRANO
19. Food generally known outside the U.S. as "lady's fingers" → OKRA
20. Start illegally, say → HOTWIRE
22. What every baseball inning starts with → NOONEON
24. "Kind of" suffix → ISH
25. Shore up the ranks → RESTAFF
27. Little pest → ANT
28. Animal with a white rump → ELK
30. Highlands hat → TAM
31. Epitome of simplicity → ABC
33. Binge → SPREE
35. "I'll ___ you!" → SUE
36. Pop-pop → GRAMP
39. Country sharing the world's longest international border → CANADA
41. Showed great pride, in a way → BEAMED
42. Desirable Vegas couple? → ACES
43. Lake in the homeland of the Washoe people → TAHOE
47. ___ Blaster (toy) → NERF
48. Inconsequential → MERE
49. Journeys by foot → TREKS
50. Ones eliciting knee-jerk reactions, informally? → DOCS
51. Exemplar → PARAGON
53. Having a strong sense of direction? → BOSSY
57. Likely oriented toward platonic relationships, in brief → ARO
58. Members of the dolphin family that prey on dolphins → ORCAS
63. Like a revving engine → AROAR
64. Skater Midori → ITO
65. Words after "ding, ding, ding" → TOAST
66. With 68-Across, "Wicked" song suggested by the answers to the seven starred clues (and whose singer is spelled by the circled letters reading from left to right) → DEFYING
68. See 66-Across → GRAVITY
70. Bronzed → GOTATAN
71. Not just yet → LATERON
72. Abjures → ESCHEWS
73. Target of urban renewal, say → EYESORE