part of speech
The abbreviations after a word in the dictionary tell you the part of speech. This is important because when looking up a word in a dictionary it is important to know how the word can function in a sentence. Some words also have different forms when it changes part of speech. For example, happy is an adjective, happiness is a noun. Common abbreviations for the parts of speech are: noun (n), pronoun (pron), adjective (adj), adverb (adv), verb (vb), conjunction (conj), preposition (prep), or interjection (interj).
Dictionary entries also contain information about the word's pronunciation, definition, origin, and alternative forms.