I pulled out 27D Dehydrated plum: PRUNE because prune just means plum but in other languages. Here’s the etymology:

prune (n.)

mid-14c., “a plum,” also “a dried plum” (c. 1200 in place name Prunhill), from Old French pronne “plum” (13c.), from Vulgar Latin *pruna, fem. singular formed from Latin pruna, neuter plural of prunum “a plum,” a dissimilated borrowing of Greek proumnon, from proumnē “plum tree,” a word probably, like the tree itself, of Anatolian origin and thus from a language of Asia Minor. Slang meaning “disagreeable or disliked person” is from 1895. Prune juice is from 1807.

Theme!

17A Pastime for armchair sports enthusiasts: FANTASYBASEBALL. Fantasy baseball is pretty much the worst. The season is so, so long. And to play it right, you gotta do rotisserie rather than head-to head, so you don’t even really know how it goes until the season ends. It’s way too much of a commitment, and how can you be a fan of the game and play roto fantasy baseball? If you throw being a functioning human, forget it. Stay away from fantasy baseball.
29A Unidentifiable protein: MYSTERYMEAT.
45A Holy site in Jerusalem: WESTERNWALL.
61A Spanish or French, but not German: ROMANCELANGUAGE.

67A What the start of 17-, 29-, 45- or 61-Across is, in a bookstore: GENRE. Fantasy novels, mystery novels, westerns, and romance novels. Also what’s a bookstore?

Finished this one in 4:13.