IPA: //ˈpeɪnˌsteɪkɪŋli//
KK: /ˈpeɪnˌsteɪkɪŋli/
In a way that involves a lot of effort and attention to detail; very carefully and thoroughly.
She worked painstakingly on her project to ensure everything was perfect.
Painstakingly → It is formed from "pain" (from Latin *poena*, meaning punishment or penalty) and "staking" (from the verb "stake", meaning to put forth effort or risk). The word "painstakingly" means doing something with great care and effort, often involving a sense of suffering or difficulty in the process.
Think of putting forth effort ('staking') that may involve some 'pain' — this helps you remember that 'painstakingly' means doing something with great care and effort.