A good college dictionary is more complete than online versions. Good ones include the principal parts of verbs (past tense, past participle. present participle, and third-person singular present tense).
Online searches of words are convenient but not as complete. For a quick definition, type a word into Google. You may need to type "definition" after the word. The Google definition will appear at the top. Using Google is fast and easy and you can click and hear the word pronounced. Google will list online dictionaries, but most of these are not any better than what Google provides. Also, there are ads that slow the loading of pages.

Advantages of a good "hard copy" college dictionary over what Google provides:

You are likely to find an explanation of the parts of speech in the front portion of a good college dictionary. Also, you will find inflected forms of the word, for example, the plural form of the word. You can also see the principal parts of verbs (past tense, past participle, present participle, and third-person singular present tense).

When a main entry in the dictionary is followed by "also" and another spelling, the second spelling is less acceptable than the first.

Unless you listen to the recording provided, you can't gather from a Google definition of words like Illinois that the "s" is silent in its pronunciation.

There are some usage notes "hard copy" dictionaries provide:

The usage label for "shut-eye" is slang.

The "hard copy" dictionary includes plural forms and past tenses (examples: the plural of "genius" is geniuses. If the verb "mimic" expresses something that happened in the past, spell it mimicked).

Don't use the word "irregardless" in a business letter; it is non-standard English.

The following plural forms are correct:
Mr. Smith asked me to type five "memoranda."
Such "phenomena" are rare.
Note: Phenomenon is the singular form.