Words sharing a historical relation.
Words in different languages related to the same root, e.g. education (English) and educación (Spanish).
Two words in different languages that are of the same descend and are similar in form and meaning.
words so similar from one language to the next as to suggest that both are variants of a single ancestral prototype.
Words that are similar in two different languages, such as nación in Spanish and nation in English. “False cognates,” on the other hand are words that appear to be similar, but which in fact have different meanings, such as French sensible, which does not mean sensible, but rather sensitive.
Words or morphs that belong to different languages but have similar sounds and meanings.
Words having a common linguistic origin. For example, café and coffee derive from the Turkish, kahve.