What is "typographic ligature"

n. (context countable typography English) A character that visually combines multiple letters, usually but not always by connecting them (making them contiguous), such as æ, œ, ß or ij; a logotype.

In writing and typography, a ligature occurs where two or more graphemes or letters are joined as a single glyph. An example is the character æ as used in English, in which the letters a and e are joined. The common ampersand (&) developed from a ligature in which the handwritten Latin letters e and t (spelling et, from the Latin for "and") were combined.