It is a noun and it means "procrastination". It is used when you put off something that has to be done because it is unpleasant or boring.
The deadline for submission of the report is approaching.
- Meg : Have you submitted the report yet?
もう報告書は提出した？ - Amy : Not yet. I've been putting it off for a while.
まだ。ずっと先延ばしにしているんだよね。 - Meg : Me neither. I'm going to stay up all night working.
私も。徹夜でやろうかな。
Ken and Leo have different opinions.
- Ken : I almost missed the deadline for the report. I have a bad habit of procrastinating.
報告書の期限に間に合わないところだった。先延ばしにする悪い癖があるんだよね。 - Leo : But you met the deadline. I don't think that you need to change your behavior.
でも、間に合ったんでしょ。別に(その癖を)直す必要ないじゃん。 - Ken : Huh, are you serious? You don't think that one should just prepare earlier?
えっ、マジ？出来る事は早めにした方がいいと思わない？ - Leo : No, I want to avoid boring things as much as possible. I don't do now what I can do tomorrow. It's my secret to enjoying life.
思わない。退屈な事はできるだけやりたくない。明日できる事は、明日やればいい(or今やる必要ない)。これが俺が人生を楽しむコツだよ。