The phrase "a lower category" is correct and usable in written English.
It can be used when discussing classifications or hierarchies, indicating that something belongs to a less significant or inferior group.
Example: "In the taxonomy of living organisms, reptiles are often considered a lower category than mammals."
Alternatives: "a subordinate category" or "a lesser category".
That hurricane - a lower Category 3 storm - left dozens dead.
For the four months the country was rated in a lower category, neither Korean Air nor its smaller rival, Asiana, could expand service to the United States or share codes with American carriers.
Just in case anyone still thought Greek debt was a sound investment, S&P, a rating agency, downgraded it to a lower category of junk earlier this month.All of which marks a change.
This is the phenomenon, currently very prevalent, of corporate travel departments insisting that those who do travel buy cheaper -- and sometimes less convenient -- air fares and stay at a lower category of hotel than the ones they may be used to.
Chronic undersleeping can lead to 15 points or more of IQ loss, which may drop us into a lower category of mental ability.
However, another important aspect to consider is that the downgrading of an EVOO to a lower category implies a big economic loss for the producers.
A higher estimate of the population risk and a lower family history category were also associated with a greater overestimation of absolute risk.
Like so many women writers everywhere, she was ignored by publishers, agonizingly, for years; she was consistently placed in a separate (lower) category by reviewers and scholars.
This is 25 cents per capita, putting Egypt in a substantially lower category compared with many other recipients of U.S. aid.
In the one corner, you've got the people (the party establishment, mostly) who appear to be of the genuine belief that Labour will only be able to win parliamentary power (hence, "really help" people) if they disguise their goodwill as a slightly lower category of hurricane to that which the Tories are offering.
The toxicity of the active ingredient is high, but many formulations will fall into a much lower category of hazard.
