Definitions and Parts of Speech
PartOfSpeech identifies the possible ways in which a word can be used.
In[1]:=

PartOfSpeech /@ {"dolphin", "root", "light"}
Out[1]=

WordDefinition provides a list of short definitions for the given word.
In[2]:=

WordDefinition["dolphin"]
Out[2]=

As expected, words having a longer list of parts of speech also tend to have a longer number of definitions.
In[3]:=

WordDefinition["root"] // Length
Out[3]=

In[4]:=

WordDefinition["light"] // Length
Out[4]=
