The easiest way to accomplish this would be to compare the similarity of the respective word embeddings (the most common implementation of this is Word2Vec).
Word2Vec is a way of representing the semantic meaning of a token in a vector space, which enables the meanings of words to be compared without requiring a large dictionary/thesaurus like WordNet.
One problem with regular implementations of Word2Vec is that it does differentiate between different senses of the same word. For example, the word bank would have the same Word2Vec representation in all of these sentences:
- The river bank was dry.
- The bank loaned money to me.
- The plane may bank to the left.
Bank has the same vector in each of these cases, but you may want them to be sorted into different groups.
One way to solve this is to use a Sense2Vec implementation. Sense2Vec models take into account the context and part of speech (and potentially other features) of the token, allowing you to differentiate between the meanings of different senses of the word.
A great library for this in Python is Spacy. It is like NLTK, but much faster as it is written in Cython (20x faster for tokenization and 400x faster for tagging). It also has Sense2Vec embeddings inbuilt, so you can accomplish your similarity task without needing other libraries.
It's as simple as:
import spacy
nlp = spacy.load('en')
apples, and_, oranges = nlp(u'apples and oranges')
apples.similarity(oranges)
It's free and has a liberal license!