1) An alphabet of manual signs 2) Finger spelling 3) Sign language 4) Signing 
Fingerspelling (or dactylology) is the representation of the letters of a writing system, and sometimes numeral systems, using only the hands. These manual alphabets (also known as finger alphabets or hand alphabets), have often been used in deaf education, and have subsequently been adopted as a distinct part of a number of sign languages; there ...
[n] - an alphabet of manual signs
the communication in sign language of a word or other expression by rendering its written form letter by letter in a manual alphabet.