• IPA: /ˈlaɪ.tən/, [ˈlaɪtn̩], [ˈlaɪʔn̩]

From Middle English lightnen, equivalent to light + -en.

lighten (lightens, present participle lightening; simple past and past participle lightened)

1. (transitive) To make brighter or clearer; to illuminate.

   Synonyms: light up

   to lighten an apartment with lamps or gas; to lighten the streets

2. (intransitive) To become brighter or clearer; to brighten.
3. (intransitive, now, rare) To flash lightning, to give off lightning.
   • c. 1590 (date written), G[eorge] P[eele], The Old Wiues Tale. […], London: […] Iohn Danter, for Raph Hancocke, and Iohn Hardie, […], published 1595, →OCLC ↗, [line 500]:

     Enter the Conjurer; it lightens and thunders […]

   • 1599 (first performance), William Shakespeare, “The Tragedie of Iulius Cæsar”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC ↗, (please specify the act number in uppercase Roman numerals):

     […] this dreadful night,
     That thunders, lightens, opens graves, and roars
     As doth the lion.

4. (transitive) To emit or disclose in, or as if in, lightning; to flash out, like lightning.
   • 1595 December 9 (first known performance), William Shakespeare, “The life and death of King Richard the Second”, in Mr. William Shakespeares Comedies, Histories, & Tragedies: Published According to the True Originall Copies (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC ↗, [Act III, scene 3]:

     […] behold his eye,
     As bright as is the eagle’s, lightens forth
     Controlling majesty:

5. (archaic) To illuminate with knowledge.

   Synonyms: enlighten

• Russian: осветля́ть
• Spanish: aclarar

• Spanish: aligerar

• Russian: светле́ть
• Spanish: aclarar

• German: blitzen

From Middle English lightnen, equivalent to light + -en.

lighten (lightens, present participle lightening; simple past and past participle lightened)

1. (transitive) To alleviate; to reduce the burden of.

   Sorrow can be lightened by being openly brought out.

2. (transitive) To make light or lighter in weight.
3. (transitive) To make less serious or more cheerful.
   • 1611, The Holy Bible, […] (King James Version), London: […] Robert Barker, […], →OCLC ↗, Psalms 34:5 ↗:

     They looked unto him, were lightened: and their faces were not ashamed.

4. (intransitive) To become light or lighter in weight.
5. (intransitive) To become less serious or more cheerful.

• French: alléger
• German: erleichtern
• Italian: alleggerire
• Portuguese: aliviar
• Russian: облегча́ть
• Spanish: aliviar

• Portuguese: aligeirar, aliviar
• Spanish: aligerar

• Portuguese: aligeirar
• Russian: смягча́ть

• Spanish: aligerar

From light + -en.

lighten (lightens, present participle lightening; simple past and past participle lightened)

1. To descend; to light.
   • Book of Common Prayer

     O Lord, let thy mercy lighten upon us.

• alight