light up

present singular third person lights up · participle present lighting up · participle past lit up · past lit up · participle past rare lighted up · past rare lighted up

1. transitiveTo illuminate, to bring light to something, to brighten.

   I've never seen a supernova blow up, but if it's anything like my old Chevy Nova, it'll light up the night sky.

   2001, J. Stewart Burns, “Roswell That Ends Well”, in Futurama, season 3, episode 19, spoken by Philip J. Fry (Billy West)

   2 more examples

   The deafening claps of thunder and the dazzling flashes of lightning which lit up the ghastly scene testified that the artillery of heaven had lent its supernatural pomp to the already gruesome spectacle.

   Episode 12, The Cyclops

   The illumination was organised by Martin Whyte from events company The Stage Group, fulfilling a long-held ambition of his to light up the 21-arch Scottish structure.

   2020 April 22, “Network News: Glenfinnan turns blue to honour NHS workers”, in Rail, page 9

   Synonyms: lighten, alight, belight, beshine, bright, enlighten, fire, illume

2. intransitiveTo start to emit light; to become activated as a light source.

   When we cranked up the engine, the fire warning light lit up.

   2009, President Nixon's Pilot, Jim Bell, in The Propinquity Effect →ISBN

   Synonyms: gleam, beam, beshine, gleam, glow, illuminate, illumine, shine

3. figurativelyintransitiveTo show an increase in activity or a brightening of mood.

   He saw Mary and his face lit up.

   1 more example

   Clara's eyes lit up at this highly unusual occurrence.

   1956 [1880], Johanna Spyri, Heidi, translation of original by Eileen Hall, page 84

4. transitiveTo ignite.

   Absence might cure it, or a second mistress / Light up another flame, and put out this.

   1712 (date written), [Joseph] Addison, Cato, a Tragedy. […], London: […] J[acob] Tonson, […], published 1713, →OCLC, Act I, scene iv, page 12

   Synonyms: inflame, kindle, aflame, alight, conflagrate, fire, fire up, ignite

5. intransitiveTo light a cigarette, pipe, etc.

   Smoking in this building is not allowed, so I always step outside to light up.

   3 more examples

   The cleaner worked, of course, at nights. He had to coal and light up the engine, as well as clean it, for the next day's work, which commenced with a light run to Barnham to "bring in the goods" from that station at about 6.30 a.m.

   1952 February, J. Pelham Maitland, “Locomotive Working on Sussex Branches Fifty Years Ago”, in Railway Magazine, page 84

   On the morning after the one-day strike, October 4, one of the Type 4s on crew-training, No. D169, was appropriated to head the 3 a.m. mail to Hull, as no steam locomotive had been lit up and the usual Hull Type 3 was not available; [...].

   1962 December, “Motive Power Miscellany: North Eastern Region”, in Modern Railways, pages 422, 425

   where a group of women rolled up to enjoy the free plonk and spill out on to the pavement to light up and chat each other up

   2019, Bernardine Evaristo, Girl, Woman, Other, Penguin Books (2020), page 15

   Synonyms: spark up

6. transitiveTo light a cigarette, pipe, etc. for (someone).

   Then I tried simply holding unlighted cigarettes, continually rejecting offers by well-meaning friends to light me up. Nothing worked.

   2008 December 17, Benjamin Bederson, “Read the Warning, Light a Cigarette?”, in The New York Times, New York, N.Y.: The New York Times Company, →ISSN, →OCLC, archived from the original on 18 Sep 2025

   2 more examples

   [He] accepted a cigar from one of his timid admirers. They followed him like Kindergärtner as he pointedly moved away from the Owl before allowing someone to light him up.

   1976, John Kelly, The Wooden Wolf, New York, N.Y.: Golden Apple Publications, published 1983, →ISBN, page 212

   It was 3-0 to us and they were standing next to me, so I got the old cigar out and said to Buzzer (Nicky Summerbee), ‘Light me up, son. We’re in the Premiership’.

   2020 July 25, Stuart James, quoting John Moncur, “‘For them, it was a fairytale. For us, a nightmare’ – inside three play-off epics”, in The Athletic, New York, N.Y.: The New York Times Company, →ISSN, →OCLC, archived from the original on 18 Sep 2025

7. transitiveTo make happy.

   You are a shining light, and you light up my life.

   2001, Ash, Shining Light

   1 more example

   "It lights me up, make me happy. Sometimes I go home, go in my room and cry with joy,"said Hudson smiling

   2010, WLTX.com, Young Girl Continues Bike Giveaway Tradition, 25 Nov 2010

   Synonyms: cheer up, happify, make someone's day, beatify, enrapture, begladden, blissen, bright

8. transitiveTo introduce (someone to something), to make someone aware of or interested in something; turn on.

   Those clauses aren't all that uncommon these days; they were protecting thousands of gay and lesbian people before there were any city gay rights ordinances. That kind of stuff lit me up to the labor movement.

   1990 February 4, Pam Mitchell, quoting Gerry Scoppettuolo, “Pro-Union And Queer”, in Gay Community News, volume 17, number 29, page 17

   1 more example

   I never troll the other side but being in Florida for a few days & seeing the dude with the Gadsden “Don’t Tread on Me” shirt really lit me up to the reality of this nightmare we’re all trying desperately to survive & to keep our precious Democracy.

   2024 March 2, @Hannahsbenz17, Twitter

9. slangtransitiveTo open fire on a target or group of targets, especially with rockets, a flamethrower, etc.

   telling me to light it up if it didn't stop approaching

   1 more example

   The back plating looks vulnerable, light that sucker up!

   2007 September 25, Bungie, Halo 3, spoken by Marcus Stacker (Pete Stacker), Microsoft Game Studios, Xbox 360, level/area: The Ark

10. USslangtransitiveTo shock (someone) with a stun gun.

    Synonyms: tase

11. USslangtransitiveTo activate the emergency sirens on a police vehicle in order to pull someone over.

    I guess he doesn't realize who's behind him, because the way he's darting and weaving, he's practically begging me to light him up.

present singular third person lights up · participle present lighting up · participle past lighted up · past lighted up

1. transitivenauticalTo loosen, slacken, or ease off.

   to light up the jib-sheets