Siamese means 'As Couples or In Tandem'. That is, those who are a Couple work As Couples, and the others work In Tandem to do the given call.

Siamese Touch 1/4 之前   Siamese Touch 之后   Siamese Arm Turn 1/4 之后 (完成)

Siamese Explode The Wave 之前   Siamese Explode 之后   Siamese Right Pull By 之后 (完成)

Sometimes it is difficult to determine who is paired with whom within the Siamese unit. From a 1/4 Box (see the left-most diagram below), dancers and are often tricked into thinking they are part of a Tandem unit when in fact they are part of an As Couples unit. Also, the dancers and are often tricked into thinking they are working in a Tandem unit with dancers and (respectively).

Siamese Follow Thru 之前   Siamese Extend 之后   Siamese Arm Turn 1/4 之后 (完成)

As Couples CONCEPT [A1]: Dancers side-by-side and facing the same direction (i.e., a Couple) work as a single dancer to do the given call.

参见 Tandem CONCEPT [C1] 并做 Solid CONCEPT [C2].