puzzle

 ACROSS

  1 The "T" of MIT, informally

  5 Tomb raider Croft

  9 Block, like a river

 14 Workplace inspection org.

 15 Carded

 16 Absinthe ingredient whose letters are all in the word "absinthe"

 17 Assist in the gym

 18 Trainer working on Peke performance?

 20 Like some superheroes

 22 Brand of cold brew?

 23 Singer DiFranco

 24 Adored person

 26 Worked well together

 30 Nobelist Sadat

 32 Not much

 34 Smelter's material

 35 Seemingly forever

 36 Former U.S. Poet Laureate Dove

 37 Squeak-stopping liquid

 38 Insurer acquired by CVS Health

 40 Secretly add to an email thread

 41 What matching ends of magnets do

 43 Sch. hidden in "walrus mustache"

 44 Former Iranian ruler

 46 Snoozefest

 47 Assistance

 48 Window frame filler

 49 Counterpart of urban

 51 Program for a future doc

 53 "You've gotta be kidding!"

 55 Low-___ image

 57 Outflow's opposite

 59 ___ Vader of "Star Wars"

 61 Piece containing a take

 65 Disneyland attraction

 66 Protrusion

 67 Mimics

 68 Name hidden in "rotten idea"

 69 Deduce

 70 "Insecure" star Rae

 71 A long while


DOWN

  1 1900 Puccini classic

  2 Nacion de Barcelona

  3 Practice piece by composer Frederic (In this clue's answer, see letters 4-7)

  4 Loathe

  5 Tupperware piece

  6 Marinated Filipino dish

  7 Habitual visits to 25-Down (... letters 5-9)

  8 Adderall might be prescribed for it

  9 Purposefully avoided, like an issue (... letters 4-8)

 10 South American range

 11 "Cool" amount of money

 12 ___ as directed

 13 "As ___ my last email ..."

 19 Point toward

 21 "The People's Princess" (... letters 5-9)

 25 Some hold MD degrees

 27 Stud alternative (... letters 4-7)

 28 Southernmost Great Lake

 29 Big name in PCs

 31 Took the gold

 33 ___-tac-toe

 38 "Stat!"

 39 Qatari leader

 40 Forbid

 42 Goof up

 45 Wasn't given a choice

 46 Dude

 50 Not bring up again

 52 Tiny fly

 54 Viral GIFs, e.g.

 56 Loses a coat?

 58 Jai ___

 60 Region

 61 Kimono sash

 62 "Velcro ... what a rip-off," e.g.

 63 Seasonal worker?

 64 Secretive org.

solution