Learn English – “high-reliable”, “highly reliable”, or something else

american-englishcompoundsorthography

There was a discussion with my colleagues about a paper that I am currently writing and in which I use phrases like "a high-reliable system architecture". Some of my colleagues hold the view that this is wrong and "a highly reliable system architecture" should be used instead, while others think that the first version is fine, too.

Is the first variant correct?

Best Answer

It should be highly reliable.

Reliable is an adjective which is modified by highly. Adverbs ending in -ly do not take hyphens.

highly [adverb indicating the level of reliability]
reliable [adjective describing system architecture]

You would use a hyphen if speaking of a high-maintenance system architecture:

high [adjective describing maintenance]
maintenance [noun]
high-maintenance [compound adjective describing system architecture]

Without the hyphen or -ly ending you would have a high meaning tall/up in the air.