Meaning of the word add-in in English

What does add-in mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

add-in

US /æd ɪn/
UK /æd ɪn/

Phrasal Verb

to include something extra when calculating a total or considering a situation

Example:
Don't forget to add in the cost of shipping when you calculate the total.
We need to add in more time for unexpected delays.