  This paper describes a topological search for an invisibly decaying Higgs
boson,H, produced via the Bjorken process (e+e- -> HZ). The analysis is based
on data recorded using the OPAL detector at LEP at centre-of-mass energies from
183 to 209 GeV corresponding to a total integrated luminosity of 629pb-1. In
the analysis only hadronic decays of the Z boson are considered. A scan over
Higgs boson masses from 1 to 120 GeV and decay widths from 1 to 3000 GeV
revealed no indication for a signal in the data. From a likelihood ratio of
expected signal and Standard Model background we determine upper limits on
cross-section times branching ratio to an invisible final state. For moderate
Higgs boson decay widths, these range from about 0.07pb Mh = 60GeV) to 0.57pb
(Mh = 114GeV). For decay widths above 200GeV the upper limits are of the order
of 0.15pb. The results can be interpreted in general scenarios predicting a
large invisible decay width of the Higgs boson. As an example we interpret the
results in the so-called stealthy Higgs scenario. The limits from this analysis
exclude a large part of the parameter range of this scenario experimentally
accessible at LEP2.
