Marked by or requiring great pains; very careful and diligent. See Synonyms at meticulous.(adjective)
Extremely careful and diligent work or effort.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "painstaking" in a sentence
"However, the sad story of the Yaquis 'fate, at the hands of the Mexican government itself, was related in painstaking detail in a book entitled Barbarous Mexico, published by an American, John Kenneth Turner, in 1911."
"Not only did the doctor who did my root canal explain, in painstaking detail, what would happen and why, I had to listen to a little lesson about possible risks and sign a whole bunch of papers saying I understood the risks and was OK with them."
"It will explain, in painstaking detail, both why I tend to go ballistic on people who are a little pushy with their advice, and also why so many people were very very upset about the OSBP proposal."