Puzzle
ACROSS 1 Word repeated before "sis boom bah"
4 Only a female one can sting
8 Latin clarification
13 "Of course!"
15 "Quickly!"
16 Any Best Picture winner
17 Amount with no wiggle room (see letters 1 to 3, 6 to 9)
19 One of the Pointer Sisters
20 Cold comfort?
21 Deer skull extension
22 Athos, to Aramis
23 Cold side at a deli
24 Palindromic drink
27 Milk-producing animals from France's mountains (3 to 6, 8 to 10)
33 Made tracks
35 Pre-stereo
36 Weasleys' owl
37 Edible submarine
38 Colorful card game
39 Irritate
40 Protective suit
42 Takes home
44 Big name in locks
45 Appliance combination that can be stacked (2 to 4, 8 to 10)
48 Retired flier: Abbr.
49 Vow renewal vows
50 AFL's partner
52 Weekly medical journal, with "The"
55 "___: Endgame" (2019 Marvel Studios film)
60 No longer groggy
61 Tree texture, or a hint to each starred answer's pair of hidden words
62 Internet connection device
63 Start the pot
64 Conclusion starter?
65 Enjoys toys
66 Kernel, e.g.
67 Test site
DOWN 1 Widespread
2 Largest continent
3 German word that doesn't rhyme with "sir"
4 "Saving Private Ryan" or "Dunkirk"
5 Skeptical response
6 Anatomical pouches
7 N95 masks and such, briefly
8 "Everything gets done"
9 "It's all right!"
10 Live the wrong way?
11 Web search result
12 Cloth concern
14 Jane Austen heroine Woodhouse
18 Mountain lion
21 Drink that may be amber
23 Stuck-up
24 "Phooey!"
25 Drama with 30-Down
26 Wavy 'dos
28 Flour bag measures
29 Word before "circle" or "peace"
30 Long solo songs
31 Bridge payments
32 Messy weather
34 Whatchamacallit
41 Cashes in
43 Officially withdrew
46 Root problem
47 The letter "O" resembles one
51 Folklore monster
52 Floor or table fixture
53 G.I. no-show
54 Zilch
55 Top-notch
56 November 2020 choice
57 Rank above viscount
58 Capital of Latvia
59 Highbrow person
61 "Now where ___ I?"
Solution