A word, in the sense of a dictionary entry. Distinct string of letters may be forms of the same lexeme (‘fills’, ‘filled’, ‘filling’); conversely, identical strings of letters (bank, the institution, bank of the river) may be forms of different lexemes, since they would standardly be thought of as different words, i.e. having very different senses, in dictionaries. However, the lexicographic principles by which to count words as the same or different are not cut and dried.