An is the fourteenth letter of the Mandaic alphabet and writes n, a voiced alveolar nasal. It joins on both sides, so it takes a full set of four shapes according to its place in a connected run and never forces the run to restart.
Its name is one of the regular ones, formed from the sound with a preceding a, as ab, ag, ad, ah and the rest are. The fish that stands behind Syriac nun and Hebrew nun has no counterpart in the Mandaic name, which describes a pronunciation and nothing further.
The fourteenth place is the one nun holds in Hebrew, in Syriac and in older Aramaic, and the correspondence runs through the whole of the first twenty-two signs, so a reader who knows one Aramaic alphabet can map the Mandaic order onto it letter by letter without recognising a single shape.
In Hebrew and Syriac the fourteenth letter carries the numeral value fifty, and in Hebrew it also has a separate final form counted apart from the twenty-two. Mandaic has neither. It records no numeral use for its letters at all, and it has positional forms rather than final letters, so the two things that make the fourteenth letter distinctive in Hebrew are both absent here.
Because an joins on both sides it is one of the letters that keeps a connected run going, so a long Mandaic word containing several of them can carry a single unbroken stroke across most of its length before a right-joining letter finally breaks it.