Parts of Speech
Parts of speech indicate how a word functions in a sentence. Dictionary entries tell you what part of speech a word isnoun, verb, adjective, and so on. The part of speech is abbreviated and printed in italics. Your dictionary provides a full list of abbreviations. The following are the most common abbreviations for the parts of speech:
Parts of Speech adj
adv
conj
interjadjective
adverb
conjunction
interjectionn
prep
pron
v, vi, vtnoun
preposition
pronoun
verb
Read again the sample dictionary entry for herbicide.
As the entry shows, the word herbicide is a noun. Two other forms of the word are identified as an adjective (herbicidal) and an adverb (herbicidally).