refer to specific shades of meaning. For instance, the word , naosu, when written , means "to heal an illness or sickness". When written it means "to fix or correct something". Sometimes the distinction is very clear, although not always. Differences of opinion among reference works are not uncommon; one dictionary may say the kanji are equivalent, while another dictionary may draw distinctions of use. As a result, native speakers of the language may have trouble knowing which kanji to use and resort to personal preference or by writing the word in hiragana. This latter strategy is frequently employed with more complex cases such as もと moto, which has at least five different kanji: , and , the first three of which have only very subtle differences. Another notable example is sakazuki "sake cup", which may be spelt as at least five different kanji: , and ; of these, the first two are common—formally is a small cup and a large cup. Local dialectical readings of kanji are also classified under kun'yomi, most notably readings for words in Ryukyuan languages. Further, in rare cases gairaigo (borrowed words) have a single character associated with them, in which case this reading is formally classified as a kun'yomi, because the character is being used for meaning, not sound. Ateji Ateji (当て字, 宛字 or あてじ) are characters used only for their sounds. In this case, pronunciation is still based on a standard reading, or used only for meaning (broadly a form of ateji, narrowly jukujikun). Therefore, only the full compound—not the individual character—has a reading. There are also special cases where the reading is completely different, often based on a historical or traditional reading. The analogous phenomenon occurs to a much lesser degree in Chinese varieties, where there are literary and colloquial readings of Chinese characters—borrowed readings and native readings. In Chinese these borrowed readings and native readings are etymologically related, since they are between Chinese varieties (which are related), not from Chinese to Japanese (which are not related). They thus form doublets and are generally similar, analogous to different on'yomi, reflecting different stages of Chinese borrowings into Japanese. Gairaigo Longer readings exist for non-Jōyō characters and non-kanji symbols, where a long gairaigo word may be the reading (this is classed as kun'yomi—see single character gairaigo, below)—the character has the seven kana reading senchimētoru "centimeter", though it is generally written as "cm" (with two