Mam [mam] 'grandfather' or 'grandson', is a pan-Maya kinship term as well as a term of respect referring to ancestors and deities. In Classic period inscriptions, the word mam appears to be used mainly to introduce the name of a grandfather, grandson, or ancestor, often a king.^[1] Ethnographically, Mam refers to several aged Maya deities:

• (i) In Kekchi-speaking Belize, 'Mam' is a general designation for the mountain spirits; four Mams were specifically associated with the four corners of the earth (see Bacab).^[2]
• (ii) In the Kekchi-speaking Alta Verapaz of Guatemala, one of the Mams is a greatly feared mountain spirit associated with earthquakes and inundations. An image of this Mam was apparently buried during the Holy Week.^[3]
• (iii) Among the Huaxtec Mayas (Huastec people), the Mams or Mamlabs are earth deities; there are three or four of them, the most important one (Muxiʼ) being the violent originator of the rainy season.^[4]
• (iv) Among the Tzutujil Mayas of Santiago Atitlán, the Mam Maximón is a deity of merchants and travellers and of witchcraft. Assimilated to Judas, he is especially venerated during the last days of the Holy Week, and discarded afterwards.^[5]
• (v) In 16th-century Yucatán, 'Mam' was also the designation of a straw puppet set up and venerated during the five unlucky days (Uayeb) at the end of the year (Cogolludo), when witchcraft was thought to be prevalent; at the conclusion of this period, the straw figure was discarded.^[6][2]

The Mayanist J.E.S. Thompson referred to Mam (ii) as the evil Mam, an unfelicitous term redolent of Judaeo-Christian dichotomies. Thompson further believed the Mams (ii), (iv) and (v) to represent the same deity.^[7]

The Mams are likely to have had their counterparts within the small Classic Maya group of aged deities consisting of God D (Itzamna), the various representatives of God N (Bacab), and God L. A corresponding concept in Aztec religion would be Huehueteotl ('old god', 'ancient god').