pre‧vi‧ous‧ly S3 W2 AC / priviəsli / 副词

before now or before a particular time :

Almost half the group had previously been heavy smokers.

two days/three years etc previously (= two days, three years etc before )

Six months previously he had smashed up his car.

THESAURUS

before earlier than something or someone : She could read before she started school. | Do you want to have a shower before me?

prior to formal before something happens : Please arrive at the airport two hours prior to departure.

by no later than a particular time or date : The children are usually in bed by 9 o’clock. | We have to be out of our hotel room by 10 o’clock.

earlier before now, or before the time you are talking about : I saw her earlier. | I had sent the letter earlier in the week.

previously before now, or before a time in the past : He previously worked as an electrician. | The show starred a previously unknown actress called Jennifer Aniston.

in advance before something happens – used especially when talking about the arrangements for something : Let me know in advance if you are going to be late. | The landlord wants three months’ rent in advance.

beforehand ( also ahead of time ) before something happens, especially so that you are ready : I wish we had known about all this beforehand. | It’s always best to decide beforehand how much you want to pay.