dispensable(able to be done without; able to be expended; easily replaced) adjective [UK: dɪ.ˈspen.səb.l̩] [US: ˌdɪ.ˈspen.səb.l̩]
expendable(not essential or mandatory) adjective [UK: ɪk.ˈspen.dəb.l̩] [US: ɪk.ˈspen.dəb.l̩]
imprescindibleadjective
indispensable(absolutely necessary) adjective [UK: ˌɪn.dɪ.ˈspen.səb.l̩] [US: ˌɪn.də.ˈspen.səb.l̩]The graveyards are full of indispensable men. = Los cementerios están llenos de personas imprescindibles.