All 3 Uses

laboratory
in
The Scarlet Letter
(Edited)

On the other side of the house, old Roger Chillingworth arranged his study and laboratory: not such as a modern man of science would reckon even tolerably complete, but provided with a distilling apparatus and the means of compounding drugs and chemicals, which the practised alchemist knew well how to turn to purpose.
p. 116.9 *

laboratory = workplace for scientific or medical research
According to the vulgar idea, the fire in his laboratory had been brought from the lower regions, and was fed with infernal fuel; and so, as might be expected, his visage was getting sooty with the smoke.
p. 118.2
He therefore still kept up a familiar intercourse with him, daily receiving the old physician in his study, or visiting the laboratory, and, for recreation's sake, watching the processes by which weeds were converted into drugs of potency.
p. 120.8

Definitions:

(1) (laboratory)
a workplace where people do scientific or medical research, or produce drugs or chemicals

or (as an adjective): related to such a place
(2) (meaning too rare to warrant focus)
Much more rarely, lab can be used as an abbreviated way of saying Labrador retriever. It is also a rare last name and may indicate someone's initials.