nonsingleletter

Nonsingleletter is a term used in linguistics and computer text processing to describe any textual token that consists of more than one letter. It is the complement to single-letter tokens, such as the English pronoun I or the article a, which are the only one-letter tokens in normal orthography. The term is not widely standardized, but it appears in some datasets and algorithms that classify tokens by length or by character type.

In practice, a nonsingleletter token may be a word such as cat, house, or algorithm, and it may also include punctuation-adjacent forms if the counting method treats letters as characters. Some tokenizers count letters only, ignoring digits or punctuation; others treat a token like co-op or e-mail as more than one letter. In many languages, single-letter words are relatively rare, but exist (for example, I and a in English). Consequently, nonsingleletter tokens cover the majority of ordinary words.

Applications include filtering, frequency analysis, or linguistic studies where length-based segmentation matters. The term also appears in discussions of tokenization schemes, where distinguishing short and long tokens can influence model vocabulary and processing efficiency.

Limitations: Because "letter" definition can vary by language and encoding, the exact boundary of what constitutes a nonsingleletter token depends on the counting rules used. See also: single-letter word, tokenization, natural language processing.