One of the mysteries of the English language finally explained.
1‘architects and engineers were all working pro bono for the nonprofit museum’
free, gratis, unpaid, unrewarded, unsalaried, free of charge, without charge, for nothing, at no cost, without payment, for the common good
gratuitous, complimentary, voluntary, volunteer
informal for free, on the house
British informal buckshee
In this article we explore how to impress employers with a spot-on CV.