soli-, sol- +

(Latin: one, alone, only)

solitarian
A recluse, a hermit.
solitariness
The state of being solitary or alone; the fact of being or dwelling apart from others.
solitary
1. Done without the company of other people.
2. Preferring to be or live alone.
3. Existing as the only one of its kind.
4. In zoology, used to describe animals that live alone or in pairs rather than in colonies or social groups.
5. In botany, a reference to flowers that grow singly rather than as a cluster.
solitron
A solitary wave; a quantum or quasiparticle propagated in the manner of a solitary wave.
solitude (s) (noun), solitudes (pl)
1. The state of being alone, separated from other people, whether considered as a welcome freedom from disturbance or as an unhappy loneliness.
2. A quality of quiet remoteness or seclusion in places from which human activity is generally absent.
3. A remote or uninhabited place.
solitudinarian
Someone who likes to be alone; a recluse.
solitudinary
Characterized by living alone or by solitude.
solitudinize
To render solitary.
solitudinous
solivagant (adjective), more solivagant, most solivagant
1. Roving around alone: There are historical stories about solivagant individuals who were rambling around in California in search of gold.
2. Characterized by doing things by oneself: Shirley tended to be a very solivagant person when she was preparing for examinations at the university.
solivagous (adjective), more solivagous, most solivagous
Drifting around by oneself or being alone as someone who goes here and there; being solitary: Sharon has seen someone who appears to be a solivagous man because he is always going from his cottage and into a neighborhood store and then back again, always by himself and never with anyone else.
solo
1. A performance by a single artist such as a musician, singer, or dancer with or without accompaniment.
2. An action or feat carried out by one person alone, e.g., a flight in an aircraft or a climb up a mountain.
soloist
Anyone who performs a solo.
solus (masculine) (adjective), sola (feminine) (not comparable)
By oneself, separate, or alone; used especially as a stage direction: "During the rehearsal, the director of the drama told the actor that in the next scene he would present his solus character."
sullen
1. Showing a bad temper or hostility by a refusal to talk, behave sociably, or cooperate cheerfully.
2. Dull and gray because of clouds, fog, or haze; such as, sullen ocean skies.
3. Moving slowly: "We saw a sullen stream while hiking in the country side."
4. Etymology: an alteration of Middle English soleyn, "unique, singular"; from Anglo-French solein, "alone", it was formed on the pattern of Old French soltain, from Old French soul, "single". The sense shift in Middle English from "solitary" to "morose" occurred between about 1380 and 1400; which in turn came from Latin solus, sol-, "sole, single"; which was the original English sense;.