The word 'frequently-joined' is a compound adjective formed from 'frequently' and 'joined'. 'Frequently' originates from the Latin word 'frequentia', meaning 'a crowd, multitude', and 'joined' comes from the Latin 'jungere', meaning 'to join'.

'Frequently' evolved from the Latin 'frequentia' through Old French 'frequent', while 'joined' evolved from the Latin 'jungere' through Old French 'joindre'.

Initially, 'frequently' meant 'in large numbers', and 'joined' meant 'to unite'. Over time, 'frequently-joined' came to mean 'often connected'.