
• (adv.) In a near relation in place, time, degree, etc.; within a little; almost. • (adv.) In a near relation in place, time, degree, etc.; within a little; almost.
Found on 
http://thinkexist.com/dictionary/meaning/nighly/
 Nigh'ly  adverb
Nigh'ly  adverb   In a near relation in place, time, degree, etc.; within a little; almost. [ Obsolete] « A cube and a sphere . . . 
 nighly of the same bigness.» 
 Locke. Found on 
http://www.encyclo.co.uk/webster/N/21
  No exact match found.