What does "reliable" mean?

1. (trustworthy or dependable) someone or something you can trust to behave well or work correctly. 2. (data transmission) a system that makes sure information reaches its destination safely. 3. (a dependable person or thing) a person or thing that you can always depend on.

reliable

adj. · n.

US //ɹiˈɫaɪəbəɫ// UK //ɹɪlˈaɪəbəl// re·li·able

1 trustworthy or dependable (adj.)
B1 Intermediate

someone or something you can trust to behave well or work correctly.

consistent in performance or behaviour; able to be trusted to do what is expected.

Example

My old car is very reliable and has never broken down on a long trip.

Example

The company is looking for a reliable contractor who can guarantee the project will be finished before the winter holidays.
2 data transmission (adj.)
C1 Advanced Technical Computing

a system that makes sure information reaches its destination safely.

referring to a protocol that ensures data packets reach their destination or notifies the sender of failure.

Example

A reliable network connection is essential for making clear video calls.

Example

TCP is considered a reliable transport protocol because it manages retransmissions to ensure that the data stream remains intact.
- guaranteed
- secure
- unreliable

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3 a dependable person or thing (n.)
B2 Upper Intermediate Informal

a person or thing that you can always depend on.

an entity that is consistently dependable; often used in the phrase 'old reliable'.

Example

When the new printer broke, we had to use 'old reliable' in the corner.

Example

Among all the flashy new gadgets, this manual typewriter remains the office reliable whenever the power goes out.
- mainstay
- stalwart

Origin

From rely + -able.

Word family

Adjectivereliable
Adverbreliably