lighten up
verb1
Idiomatic To make (something) or to become less serious and more cheerful or casual; to relax.
- I wish he'd lighten up a bit and realize that we were only joking.
- The mood at work has been tense, so he's looking for ways to lighten it up.
2 more examples
- Sondheim's sense of life — which is pretty pessimistic (I don't think that anyone ever ends happily ever after in a Sondheim musical) — is brought through without trying to lighten it up.1983 August 6, Michael Bronski, “Gay Sensibility, Straight Imitation”, in Gay Community News, page 8:
- you lighten up my heart when I start to cry2008, Adele, First Love:
2
To lighten (something): to decrease its weight.
- Near-synonym: slim down
- He can't get any more power out of it [his drag racer], so now he's looking for ways to lighten it up.