somni-, somno-, somn-, -somnia, -somniac

(Latin: sleep, sleeping; dreams, dreaming)

somnolentia (s) (noun); somnolentias (pl)
A strong desire to sleep; an uncontrollable drowsiness: Somnolentia is a prolonged transition from sleep to waking up, with partial alertness, disorientation, poor coordination, and sometimes an excited or violent behavior.
somnolently (adverb), more somnolently, most somnolently
Conveying a sleepily or drowsy manner.
somnolescence (s) (noun), somnolescences (pl)
A preference or a strong desire to sleep.
somnolescent (adjective), more somnolescent, most somnolescent
Characteristic of being partly asleep or being sluggish and uncontrollably getting very sleepy.
somnolism (s) (noun), somnolisms (pl)
Another term for hypnotism.
somnophilia (s) (noun), somnophilias (pl)
A fondness for sleeping or a great desire to be slumbering.
somnophilist (s) (noun), somnophilists (pl)
1. A collector of beds.
2. A person who loves to sleep.
somnorine (s) (noun), somnorines (pl)
A vision, or visions, that appear during sleep while dreaming.
Somnus (s) (noun) (a proper noun, no plural)
The Latin god of sleep. The Greek name was Hypnos.

Somnus is said to have lived in “a cave from which all light was excluded, and to which all sounds and noises of the world penetrated either not at all or dully muffled.” The rooster never called there to Aurora, nor was there a watchdog or goose to disturb the silence. No wild beast, nor cattle, nor branches rustled with the wind, nor sound of human conversation or clamor of tongues broke the stillness.

There was only the gently flowing river Lethe, the river of forgetfulness, and by its murmur enticed those who heard it to sleep. Poppies grew by the door of the cave, from whose juices Night distilled slumbers that she scattered over the darkened earth. There was no gate to creak on its hinges, nor any watchman to call out.

Somnus lay asleep on a couch of black ebony adorned with black downy-soft plumes and black curtains. Around him lay dreams, some even sat on his head; resembling various forms, as many as the harvest produces stalks of grain, or the forest leaves, or the seashore grains of sand.

Whenever anyone was able to see Somnus, he was holding a poppy of forgetfulness or a horn from which trickled the drops of slumber. His twin brother was Mors (Greek: Thanatos) or Death, often represented as a quiet, pensive youth with wings, who stood beside a funeral urn decorated with a funeral wreath. Sometimes he held an extinguished torch in his hand.

Sources of information

The Classic Myths in English Literature and in Art.
by Charles Mills Gayley; Ginn and Company;
New York; 1939; pages 176-177.
and
Mythology by Edith Hamilton; New American Library;
New York; 1969, page 107.
and
Classical Myths by Max J. Herzberg;
Allyn and Bacon; New York; 1935, pages 180-181.

Related "sleep" units: dorm-; hypno-; letho-; narco-; oneiro- (dream); sopor-.