The root is:

kh – r – j

خ – ر – ج

It conveys the meaning of ‘going or being outside’.

Here are the English equivalents of the words with the root kh – r – j.

خرج kharaja – he went out (of the house)

خارج khaarij – outside

مخرج makhraj –  exit

استخراج istikhraaj extraction (e.g. of oil, coal)

خارجية khaarijiyya external affairs (pol.)