under lock and key

ADJECTIVE

captive

Synonyms

STRONGEST

caged enslaved imprisoned incommunicado

STRONG

bound

WEAK

confined ensnared in custody incarcerated jailed locked up penned restricted subjugated

Antonyms

WEAK

disillusioned free independent loose uninterested

ADJECTIVE

safe

Synonyms

STRONGEST

intact protected secure

STRONG

okay snug

WEAK

cherished free from danger guarded home free impervious impregnable in safety inviolable invulnerable maintained out of danger out of harm's way preserved safe and sound safeguarded sheltered shielded sitting pretty tended unassailable undamaged under one's wing unharmed unhurt uninjured unmolested unscathed unthreatened vindicated watched

Antonyms

STRONGEST

insecure unprotected

WEAK

dangerous exposed harmful incautious poisonous risky unguarded unsafe unthoughtful vulnerable

VERB

behind bars

Synonyms

WEAK

confined imprisoned in jail in prison incarcerated jailed put away serving time

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The sorrows that trouble him he keeps under lock and key.

From The Wall Street Journal • Dec. 4, 2025

He could provide an option on the flank, but Liverpool's wide areas appear to be under lock and key.

From BBC • Jun. 14, 2025

The driver was arrested and the van was towed away, put under lock and key at a local impound yard.

From Los Angeles Times • Mar. 18, 2025

They still use equipment the Yankees donated in 2019 during MLB’s debut in Europe — baseball’s are in sparse supply in the U.K., so the Mets keep their gameday stockpile under lock and key.

From Seattle Times • Jun. 6, 2024

Unscheduled and no longer under lock and key, he takes long walks around the city.

From "The Night Circus" by Erin Morgenstern

under lock and key

Example Sentences

Related Words