In the alignment shop I worked at, it was referred to everyone just like common knowledge as a drag link, being the long portion that connects the tie rods into 1 piece with adjusters on either or each end.
I'd always known a Pitman arm to connect to the steering box.
Drag link always connects the steering arm to the steering box (or pitman arm to be more exact). In some cases, the drag link attaches to the tie rod because there is no steering arm. The tie rods connect to two wheels together and no matter how long one of them might be, it's still a tie rod.
In most IFS setups, whether it's 2x4 or 4x4, the center link takes place of the drag link. The center link attaches between the tie rods on each side and hooks to the pitman arm (and idler arm).
There are also several goofy setups that are a combo of everything. Like '00 or so Chevy vans. They have a pitman arm that moves a drag link, that attaches to a centerlink with an idler arm on each side. Each side of the centerlink also attaches to the inner and outer tie rods on each side.
All in all, there's a ton of different setups and it's hard to nail down an exact definition of each part's name. But in the case of an old 4x4 Chevy, that big bar that connects both wheels is a left tie rod, a right tie rod, and an adjusting sleeve.
