The term 'Lexicographer's Concern' can be summed up by the crossword solution of 'USAGE', which is a five letter word. USAGE refers to the way in which words are used in a language, and is an important consideration for lexicographers. Lexicographers are responsible for creating dictionaries, and must consider the USAGE of words when deciding how to define them. Therefore, 'USAGE' is an appropriate answer to the crossword clue 'Lexicographer's Concern'.