When donations from parents pay for school computers, this is an example of the donations defraying the cost of computers.
Origin of defrayFrench défrayer ; from Old French defraier ; from de- (L de), from, off + an unverified form frai (Fr frais, plural ), expense, cost, “damages,” probably ; from Classical Latin fractum, neuter past participle of frangere, to break
transitive verbde·frayed, de·fray·ing, de·frays
Origin of defrayFrench défrayer, from Old French desfrayer : des-, de- + *frai, expense (from Latin fractum, from neuter past participle of frangere, to break; see bhreg- in Indo-European roots).
(third-person singular simple present defrays, present participle defraying, simple past and past participle defrayed)
From Middle French desfrayer, French défrayer, from dé- + Old French fraier (“to spend”).