This paper describes a topological search for invisibly decaying Higgs
bosons S0 with masses and decay widths between 1-120 GeV and 1-3000 GeV,
respectively. The Higgs bosons are assumed to be produced via the Bjorken
process ee -> S0 Z0, where only hadronic decays of the Z0 are considered.
The data analysed was recorded with the OPAL detector at the symmetric
e+e- collider LEP at CERN at centre-of-mass energies between 183 and 209
GeV, corresponding to a total integrated luminosity of 629 pb^{-1}. A scan
over the allowed parameter range revealed no indication for a signal and
therefore limits on cross section times branching fraction are set. The
results are interpreted in the Stealthy Higgs scenario, where the Higgs
boson decays predominantly into additional scalars, behaving like SM
singlet fields. The search parameters in this model are the mass of the
Higgs boson and the coupling omega of the Higgs boson to the hidden scalar
sector. A large part of the parameter range, which is experimentally
accessible at LEP2, is excluded.