sol

IPA/sɒl/
KK[sˈɑl]IPA/səʊl/

sol — noun

1. the step that comes fifth in a major scale, sung as the syllable sol to practise

1.nounB1
Definition

the step that comes fifth in a major scale, sung as the syllable sol to practise pitch and sight-singing

Example

Eve practiced singing the note sol until her voice matched the piano perfectly.

sing + note + sol pattern

The music teacher asked Bao to start the scale from do and stop at sol.

scale: from do to sol

Common collocations
  • sing sol
  • hit the note sol
  • the syllable sol
  • sol in the scale
Synonyms
  • soh

    British spelling used in tonic sol-fa notation; same note, different orthographic convention

  • fifth (note)

    technical term for the fifth degree of a diatonic scale; broader than the sung syllable

Usage Note

In British tonic sol-fa notation, the fifth note is often written as 'soh' to distinguish it from the word 'sol' (sun). Different solmization systems may assign slightly different pitches to the syllable sol depending on the key.

Common Mistakes

She sang a beautiful soul in the chorus.
She sang a beautiful sol in the chorus.
'soul' means the spiritual part of a person; 'sol' is a musical note.
The scale goes do-re-mi-fa-soul-la-ti-do.
The scale goes do-re-mi-fa-sol-la-ti-do.
The fifth note is sol, not soul.

2. a fluid mixture in which tiny solid particles are dispersed throughout a liquid

2.nounC1
Definition

a fluid mixture in which tiny solid particles are dispersed throughout a liquid without settling out or dissolving

Example

The lab technician prepared a silica sol by stirring fine sand particles into a beaker of water.

prepared a [substance] sol

Walid watched the blue sol turn into a gel as the temperature of the solution dropped.

sol-to-gel transition

Common collocations
  • silica sol
  • sol-gel process
  • colloidal sol
  • metal sol
  • form a sol
Synonyms
  • colloidal solution

    broader term that includes both sols (solid-in-liquid) and other colloid types

  • colloidal suspension

    emphasises that the solid particles remain suspended rather than dissolved

Antonyms
  • gel

    a semi-solid colloid in which the liquid phase is trapped within a solid network; the opposite physical state of a sol

Usage Note

A sol may transition into a gel under certain conditions (temperature change, pH shift) — this sol-gel process is widely used in materials science. The plural form is 'sols.'

sol — abbreviation

Word family

Synonym discussion

Sense: noun/1

These seven syllables — do, re, mi, fa, sol, la, ti — form the foundation of the sol-fa system for sight-singing. Each syllable represents a specific degree of the major scale. 'Sol' is the fifth degree and carries a bright, stable quality that music teachers often use to practice interval recognition with the fourth degree (fa) or the sixth degree (la). Unlike fixed-do systems where 'do' always means C, the movable-do system shifts all syllables with the key, which means the actual pitch of 'sol' changes depending on the starting note. In everyday music class settings, learners typically practise the pattern 'do-re-mi-fa-sol' as their first five-note sequence before adding 'la' and 'ti' to complete the octave.

doh (do)re ↗mi ↗fasol ↗lati

Common collocations

Phrases

  • do-re-mi-fa-sol
  • sol-fa system
  • sol-gel process

Etymology

LatinItalianEnglish

The musical sense of 'sol' traces back to the 11th-century Italian monk Guido of Arezzo, who created the solmization system from the first syllables of each line of the Latin hymn 'Ut queant laxis.' The syllable 'sol' came from the line beginning 'Solve polluti' ('cleanse the stained lip'). The chemistry sense of 'sol' is a 19th-century shortening of 'solution,' from Latin 'solutus' (loosened, dissolved), past participle of 'solvere' (to loosen). The abbreviation 'sol.' for 'soluble' follows the same Latin root. These two meanings — one medieval liturgical, one modern scientific — are historically unrelated but happen to share the same three-letter form in English.