Yut is the tenth letter of the Samaritan alphabet, the first of the tens, and carries the numeral value ten. It writes the semivowel y. The name is the inherited Northwest Semitic one behind Hebrew yod, and the gloss usually given for it, a hand, is a reconstruction from the word.
Its grammatical load is heavy. Yut prefixes the third person masculine of the imperfect verb, so it opens a large share of the verbs in any narrative passage; suffixed to a noun it marks the first person possessive; and it is one of the letters used as a vowel marker inside a word, standing for the i and e vowels in unpointed text. That last role is what makes an unpointed Semitic text readable at all, and it is why the same twenty-two letters can carry a language with a rich vowel system.
In the square Hebrew script the corresponding letter is the smallest sign in the alphabet, small enough that its name, by way of Greek iota, became an English byword for the least possible amount. The Samaritan letterform belongs to a different line and does not carry that reputation, but the Greek letter that inherited the sign, iota, is the same one, in the same tenth position, with the same numeral value.
The character is encoded at U+0809.