mass meeting (noun) rally: celebratory meeting
Sinonime: autonomous,
chosen,
deliberate, designful, discretional, elected, free, free-willed,
freely, gratuitous, honorary,
independent,
intended,
intentional, opted, optional, spontaneous, unasked, unbidden, uncompelled, unconstrained, unforced, unpaid, unprescribed, volitional, volunteer, willed, willful, wished, witting
Antonime: forced, involuntary,
obligatory,
unwilling