Definify.com
Webster 1913 Edition
Sightfulness
Sight′ful-ness
,Noun.
 The state of being sightful; perspicuity. 
[Obs.] 
Sir P. Sidney.
 Webster 1828 Edition
Sightfulness
SIGHTFULNESS
,Noun.
  Definition 2025
sightfulness
sightfulness
English
Noun
sightfulness (uncountable)
-  (obsolete) The state of being sightful; perspicuity.
- (Can we find and add a quotation of Sir Philip Sidney to this entry?)