This is the 112th most frequent Norwegian word.
forrige
Previous.
Here, 'forrige' is used as an adjective to specify a time in the past, indicating 'last' in reference to the previous week.
Jeg besøkte Oslo forrige uke.
I visited Oslo last week.
In this sentence, 'forrige' is used as an adjective describing a specific occurrence in the past, being 'the last time' the action of meeting occurred.
Vi diskuterte dette forrige gang vi møttes.
We discussed this the last time we met.
Here, 'forrige' qualifies 'jul' as the prior Christmas compared to the current or most recent one.