Unob*tru"sive*ness

from The Collaborative International Dictionary of English v.0.48

Unobtrusive \Un`ob*tru"sive\, a.
   Not obtrusive; not presuming; modest. -- {Un`ob*tru"sive*ly},
   adv. -- {Un`ob*tru"sive*ness}, n.
   [1913 Webster]