'randomly-collected' originates from the combination of 'randomly' and 'collected', where 'randomly' is derived from 'random', meaning 'without a definite aim, direction, rule, or method', and 'collected' is the past participle of 'collect', meaning 'to gather together'.

'randomly' evolved from the Middle English word 'randoun', and 'collected' from the Latin 'collectus', the past participle of 'colligere', meaning 'to gather together'.

Initially, 'randomly' meant 'without a definite aim', and 'collected' meant 'gathered together'. The combination retains these meanings, indicating a gathering done without a specific order.