Meaning of “extend” - Learner’s Dictionary

extend

verb uk us /ɪkˈstend/
MAKE BIGGER [ T ]

B2 to make something bigger or longer:

We're going to extend our kitchen.
Can you extend the ladder a bit?
MAKE LAST [ T ]

to make an activity, agreement, etc last for a longer time:

They have extended the deadline by one week.
extend from/into/over, etc

to continue or stretch over a particular area of land or period of time:

a mountain range that extends down the Italian peninsula
Will the building work extend into next week?
STRETCH OUT [ T ]

to stretch out a part of your body:

She smiled and extended her hand.
extend an invitation/thanks, etc to sb formal

to give someone an invitation/thanks, etc:

I'd like to extend a warm welcome to our guests.

(Definition of “extend” from the Cambridge Learner’s Dictionary © Cambridge University Press)