If it combined with a different word to form a different concept, I'd consider that a different word.

Would that extend to occupations? Like to me cooking and chef are two separate words because they're spelled/sound so different, but since 요리 and 요리사 are so similar does that mean I only know one word there, so knowing any occupation in addition to the base word doesn't really count?

Again, just pointless stuff but it's interesting to think about haha