Fastest way to search a word in a word list?
Trie might help, it stores your "word list" like this:

              a
             / \
           [a]   a
           /      \
         [a]       h
                    \
                     e
                      \
                      [d]


And you can query by some operation like trie['a']['a']['h']['e'], which is just array index operation. It takes large memory but it's very efficient. The complexity of the query operation is $ O(n) $, n is the length of the queried string.