labor

The root labor comes from Latin labor (toil, hardship) and its verb labōrāre (to work, to struggle). The original sense was not just "work" but effortful work — the sweat and strain of pushing through something difficult. A Roman farmer in the field, an ox straining at the plow: that burden is the heart of labor.

That double idea — work + difficulty — is why the family branches in two directions.

The difficulty branch keeps the strain front and center:
- laborer / labourer — one who does the heavy physical work
- laborious / laboriously — needing great effort, slow and exhausting
- labored — done with visible effort, lacking natural ease (labored breathing, a labored joke)

The productive work branch is more abstract — work that makes something:
- laboratory — literally a "place for working," which narrowed to the scientist's workroom. (The everyday clipping lab hides the labor inside it.)
- collaborate / collaboration — con- (together) + labor = working together. Coworkers "labor as one."
- elaborate / elaboration / elaborately — e- (out) + labor = to "work out" something fully. What is worked out in detail becomes intricate (an elaborate plan) or, as a verb, to spell something out (elaborate on your idea).

One member drifted into pure metaphor: belabor — be- (thoroughly, on) + labor = to "work over" something far past the point it was needed. You don't physically toil; you keep hammering a point until everyone is tired of it.

The through-line: every labor word still carries that bead of sweat. Whether it's a construction laborer, a slow laborious climb, scientists collaborating in a laboratory, or a writer elaborating a plot — somewhere effort is being spent.

Note on spelling: British English keeps the older labour / labourer; American English dropped the u to labor / laborer. The Latinate derivatives (laboratory, collaborate, elaborate) are spelled the same on both sides.