The Collaborative International Dictionary of English v.0.48:

Webby \Web"by\, a.
   Of or pertaining to a web or webs; like a web; filled or
   covered with webs.
   [1913 Webster]

         Bats on their webby wings in darkness move. --Crabbe.
   [1913 Webster]

WordNet (r) 3.0 (2006):

webby
    adj 1: having open interstices or resembling a web [syn: lacy,
           netlike, netted, webbed, weblike, webby]