Fetching details from the dictionary...

to grow long (e.g. hair, nails)
to lengthen; to extend; to stretch
to reach out; to hold out
to straighten; to smooth out
to spread evenly (dough, cream, etc.)
to dilute; to thin out
to postpone
to prolong
to strengthen; to develop; to expand
締め切りを来週まで延ばしてもらった。
I had the deadline postponed until next week.
朝の背伸びをして体を気持ちよく延ばした。
I stretched my body by standing on tiptoe.
会議を一時間延ばすことにした。
I decided to extend the meeting by an hour.