I your iPhone is jailbroken, you can install a tweak called 'SpotDict'. Otherwise, you're out of luck.
No.
Safari
Download one
The online dictionary Seslisozluk is a browser add-on. It can be found on iGoogle, iphone, iPad and many more. It offered for almost any web browser and can be found by doing a simple search.
The search feature in Mac OS X is called Spotlight.
To search on a Mac use Spotlight. Click on the magnifying glass in the top right corner of the menu bar and enter something relevant to your search. If it is on the hard disc somewhere Spotlight will find it.
Search the dictionary
search it in a dictionary
Search it on the dictionary place :)
You can find a dictionary by typing dictionary in the search bar
Spotlight
To use the dictionary on a MacBook, you can either press Command + Control + D while hovering over a word in any app to see its definition in a pop-up. Alternatively, you can open the Dictionary app by searching for "Dictionary" in Spotlight (press Command + Space) or finding it in the Applications folder. Once open, you can search for any word to view its definition, synonyms, and related information. You can also customize the dictionaries you want to use in the app's preferences.