| EGYPTOLOGY | Study of an ancient civilisation who used hieroglyphics as a form of communication and mummification |
| INCAS | Members of an ancient civilisation who invented quipu mnemonic devices (5) |
| ANUBIS | Egyptian god of the afterlife and mummification (6) |
| MAYA | Non-Egyptian people who used hieroglyphics |
| AZTECS | Members of a people with an advanced civilization who lived in Mexico even before the conquest of Cortes |
| RADIO | From "spoke of a wheel, beam of light", a form of communication referred to as "sound"; or, a set or wireless for receiving its signals (5) |
| BACKCHANNEL | Unofficial means of communication, and a hint to each set of circled letters |
| GROWL | Vocalisation used as a form of communication by canines and felines (5) |
| ELAMITES | Members of an ancient civilisation in modern-day Iran, also known as Susiana after its capital, Susa (8) |
| MERCURY | Roman god of communication and commerce, who guided souls to the underworld (7) |
| WAGGLEDANCE | Honeybee's sequence of movements performed as a form of communication, first decoded by Karl von Frisch (6,5) |
| PHEROMONE | Chemical secreted by an animal as a form of communication (9) |
| ETRUSCAN | Language of an ancient civilisation of central Italy (8) |
| CYBERNETICS | Science of communications and automated control systems in both machines and living things |
| MORSE | Sermon, endless and confused, is still a form of communication (5) |
| INCAN | Of an ancient civilisation (5) |
| INCA | Member of an ancient civilisation (4) |
| CRETE | Island home of an ancient civilisation (5) |
| EGYPT | Site of an ancient civilization centered on the Nile river. (5) |
| SOHO | John Snow's study of an outbreak of cholera in this London West End area led to the discovery that water supplies were the means of spreading this disease |
