わざわざ
To go out of one's way (to do something not required)machine translation
Formationわざわざ + verb (an intentional, non-obligatory action)
わざわざ describes an action someone GOES OUT OF THEIR WAY to do even though it isn't required — spending extra time and effort beyond what's necessary: わざわざ駅まで届けてくれた (they went out of their way to bring it all the way to the station for me). That's why it appears constantly in expressions of thanks: 遠いところをわざわざありがとうございます (thank you for coming all this way).
The flip side: when talking about something unnecessary, わざわざ turns into "why bother": 電話で済むのに、わざわざ行く必要はない (a phone call would do — no need to go all the way there). Context decides whether the sentence is gratitude or grumbling.
Don't confuse it with わざと — also "deliberately," but with a bad meaning: intentionally doing harm or faking (わざと負けた — lost on purpose). Quick rule: わざわざ = taking the trouble (usually good, thank-worthy), わざと = on purpose (usually bad, blameworthy).
Examples
遠いところをわざわざ来てくださって、ありがとうございます。
Thank you for going out of your way to come all this way.
忘れた傘を、母がわざわざ駅まで届けてくれました。
My mother went out of her way to bring the umbrella I'd forgotten all the way to the station.
電話で済むのに、わざわざ行く必要はありませんよ。
A phone call will do — there's no need to go all the way there.