unlike (Adjective) — Marked by dissimilarity. ex. "for twins they are very unlike"
unlike (Adjective) — Not equal in amount. ex. "they distributed unlike (or unequal) sums to the various charities"
unlike (Preposition) — In contrast to. ex. "he's very friendly, unlike his father"
unlike (Preposition) — Not similar to, different from. ex. "the new one is quite unlike the old one"
unlike (Preposition) — Not typical of. ex. "most unlike her to be late"