Recently there's been a trend to apply the term "bullying" to any kind of conflict at work, for example overwork and long hours. Although some bullying behaviours may be present in these issues, in my view this dilutes and devalues the term "workplace bullying" which should be used only for the more serious cases of conflict involving a serial bully. If there isn't a serial bully involved, it's probably not bullying you're dealing with.