puzzle

 ACROSS

  1 Sign up

  5 Corp. shuffle

 10 Orangutans, e.g.

 14 Bone, on an Italian menu

 15 Fighting

 16 Folk knowledge

 17 Hundred-to-one shot, e.g. (In this clue's answer, note the first 3 letters + the last 2)

 19 Filet mignon source

 20 Empty talk

 21 Word after "aisle" or "window"

 23 Christmas bulb, briefly

 24 Tie in chess

 26 "NCIS" actor Murray

 28 Trade-___ (certain cars)

 31 Bad place to see a fox (... first 2 letters + last 2)

 36 "Las Vegas of Asia"

 38 Greek X

 39 Circle dance

 40 Rings around castles

 41 Cattrall of "Sex and the City"

 42 Fanta and Sprite

 43 Arrows, to an archer

 44 Rock grp. hidden in "free love"

 45 Election predictors

 46 Wonder Woman's secret identity (... first 2 letters + last 2)

 50 Dallas-to-New Orleans dir.

 51 King of tragedy

 52 "Twist, Lick, Dunk" cookie

 54 TikTok star Addison

 56 Intentions

 59 Give in

 63 Off-kilter

 65 Avoid elimination, or a hint to 17-, 31- and 46-Across

 67 Show of hands, maybe

 68 Full of energy

 69 Gets an A+ on

 70 Anna's sister in "Frozen"

 71 Unit of volume

 72 Prying


DOWN

  1 Tease playfully

  2 Capital of Norway

  3 "That so?"

  4 Wanderer

  5 Enthusiastic ... or a sarcastic laugh backward

  6 Greek H

  7 Takes responsibility for

  8 Drag strip event

  9 Pink Ladies' rock musical

 10 The whole shebang

 11 Foam flotation device

 12 Lake that sounds chilling

 13 Word by a paper plane icon, in Outlook

 18 Unicycle site

 22 You may count to it

 25 Porch furniture material

 27 Sound an allergist hears

 28 "Grr!"

 29 Osaka of tennis

 30 Phishing notifications, e.g.

 32 Spicy topping for a hot dog

 33 Japan's national dress

 34 Spoken exams

 35 Out of style

 37 Make amends

 42 Gettysburg Address, for one

 47 Roadside boost org.

 48 Like basic instincts

 49 Earthen bowl?

 53 Humpback's home

 54 Great review

 55 Deserter's acronym

 57 Neighbor of Algeria

 58 Funny sketch

 60 Danish shoe brand

 61 Club payments

 62 Amazon Handmade competitor

 64 Formal affirmative

 66 December 24 or 31

solution