My vocabulary is not too good. I mean I know a lot of words but I don't know a lot of their meanings. I looked up the word passion in the dictionary, and in one dictionary it lists "love or affection" as a definition, but I don't know if this is meant to be distinct from sexual desire or meant to signify other forms of love. My question is, in places where I would put the word love, can I instead put passion, or does passion only refer to sexual desire, in which case I cannot use the word? The English language does not seem to have too many synonyms that mean the same thing. Most of the time when I look up the meaning of synonyms, they mean different things. I am not sure why they are called synonyms then, or why they are grouped together, when many of them cannot be substituted for the others.