Category:Spanish nouns with irregular gender

In Spanish, nouns ending in -a are mostly feminine and nouns ending in -o are mostly masculine. Nouns ending in -ción, -sis, -tad, -dad, -tud, and -umbre are always feminine but are not as common as -a endings. A few nouns have the opposite gender to what is implied by their ending, and those belong in this category.

Feminine singular nouns which begin with a stressed a vowel sound take the masculine definite article. Since these nouns are still feminine they do not belong in this category. The most common example is agua, which in the phrase ‘the cold water’ is written ‘el agua fría’ with a masculine article but a feminine adjective afterwards. But in plural, these words come back to using feminine articles, like “ ” (“the sewage”).
 * Note 1:

Quite a few nouns take neither ending but for the purposes of this category they are considered neither regular nor irregular but unpredictable.
 * Note 2:

Some words have irregular gender only in one homonym or one sense. Some others can be either gender without changing their ending. All of these are counted as irregular. This can also be the case when one word has difference senses because it is a shortening of a longer word. For instance, the masculine "disco" can refer to a throwing disc (such as the sport discus) but can also be a shortening of the feminine "discoteca", which is a discotheque.
 * Note 3:

Words ending in -ma that are derived from Greek rather than Latin (e.g., tema, telegrama, drama, but not forma) are almost always masculine. Thus, the gender of words ending in -ma is often predictable to English speakers, as many of these words also appear in English. However, somebody unfamiliar with the Greek words would not be able to predict which words ending in -ma are feminine and which are masculine; hence, they appear in this list.
 * Note 4:

Some other suffixes or endings have always or usually the same gender. This is the case for, , or. Although not recognizable nowadays as a compound, they have a meaning relation in the original Greek (planeta: 'the one that wanders'; cometa: 'the one with tail'; atleta: 'the one who competes'; however this same ending is used also in Romance for diminutives: casa > caseta, cruz > cruceta, vela > veleta).
 * Note 5: