painstaking

Etymology

From pains + taking; see take pains. The /ˈpeɪnˌsteɪkɪŋ/ pronunciation which dominates in the United States suggests a reanalysis of the word as pain + staking.

adj

1. Carefully attentive to details; diligent in performing a process or procedure.
   All these painstaking men, considered together, may be said to have completed another species of criticism. 1781, James Harris, Philological Inquiries
   It is hoped to feature the historic vehicles to be found on the line in a future article, so that full justice may be done to the painstaking work of renovation on many of them, such as the North Eastern Railway Coach Group's NER autocoach No 3453. 1979 August, Michael Harris, “A line for all reasons: the North Yorkshire Moors Railway”, in Railway World, page 415

noun

1. The application of careful and attentive effort.
   It is not by a flight of imagination that you gain the ascents of spiritual experience. It is by the toils and the watchings and the painstakings of a solid obedience. c. 1836, Thomas Chalmers, Lectures on the Romans
   Behold what an abundant recompense attends the small processes of the earth, with the help of a little warm air; and what wealthy returns the industry of the husbandman and the florist is preparing from a few seeds and painstakings. 1852, Nathaniel Langdon Frothingham, “Sermon VI”, in Sermons in the Order of a Twelvemonth