If you notice that painstaking is composed of pains and taking, you already have a pretty clear sense of what this adjective means: to be painstaking is to be so careful—so meticulous, so thorough that it hurts.
Painstaking is most commonly paired with detail — in fact, writers might like to avoid the phrase “painstaking detail” as clichéd. In contemporary usage, the agony implied by the word often seems to be shared by both the person who makes a painstaking effort and the person confronted with the fruits of that labor: “Gertrude’s ability to appear politely interested was tested as her dinner companion related his painstaking attempts to establish himself as the true heir to the British throne.”
