last

Happening or coming after all other similar things or people.

Example: I was the last person to go there: when I went, the others were all already there.

To endure, continue over time.

Example: Summer seems to last longer each year.

To hold out, continue undefeated or entire.

Example: I don't know how much longer we can last without reinforcements.

Last week, month, year, etc. is the one that comes before this one.

Example: I didn't see you last week.