Solipsism

The theory that the self is the only reality; self-absorption (n)

Desolate

Deserted and lonely (adj)

Soliloquy

A literary or dramatic speech spoken by a solitary character (n)

Monotonous

Unvarying; lacking in variety (adj)

Monosyllabic

Having only one syllable (adJ)

Monotone

A sameness of sound, style, manner, or color (n)

Divulge

To make public (v)

Vulgar

Of the common people (adj)

Polymath

A person with knowledge of many subjects (n)

Hoi Polloi

The common people; the masses

Polyglot

A person with knowledge of several languages (n)

SOL

Latin: SOLUS

Alone (root)

MONO

Latin: MONOS

One (root)

VULG

Latin: VULGUS

Crowd (root)

POLY/POLL

Greek: POLUS

Many (root)