The phrase "a defined group of" is correct and usable in written English.
It can be used when referring to a specific, identifiable collection of individuals or items that share common characteristics or criteria.
Example: "The study focused on a defined group of participants who met the age and health criteria."
Alternatives: "a specific set of" or "a designated category of".
But he left open the possibility that the city could require all restaurants, or a defined group of restaurants, to post the calorie information.
If a defined group of people is being killed at such a rate by another defined group, then normally we would take action.
The class then collaborated on the construction of the website, using photographs made on the trip and providing commentaries for a defined group of monuments.
They also vest it in the canvassing board, and the canvassing board is composed of a certain -- a defined group of officials: a county judge, the elections supervisor, the chairman of the county commission.
The committee called on the government to explore the option of permitting a defined group of women who have been affected by state pension age changes to take early retirement, from a specified age, on an "actuarially neutral basis".
To analyze promoter regions of CYP11A1 and CYP17 for putative variations in a defined group of women with polycystic ovary syndrome (PCOS) and to study their association with androgen levels.
The TRP superfamily of ion channels is a structurally defined group of cation channels showing an enormous functional diversity [ 1].
A complicating factor is that condensed tannins are a poorly defined group of compounds (basically polymers capable of covalently binding protein) making standardised determinations in plant material difficult.
Besides being an important process for the protection of receiving waters, nitrification served as a proxy for the understanding of the behavior of a narrowly defined group of microorganisms growing on known substrates under environmental conditions.
But she cautions that Tansaekhwa was not an official movement; there was no manifesto, nor a clearly defined group of members.
