Looking up word under the cursor in Vim in OS X default dictionary
When you have two displays and one of them serve as a distractless environment for writing, make use of the second for a quick look up of word under the cursor. MacDict comes to help you. First install it:
Then use this binding so that it is easily available at your fingertips (I switched from \\\\ to , as the leader key).
map <leader>d "dyiw:call MacDict(@d)<CR>