The phrase 'can apply' is decisive. A universal need not have many currently visible instances. What matters is whether the meaning itself admits application to more than one individual.
Imagine a room with only one student. 'Student' remains universal because someone else could also fit that meaning.
There is one individual in the room, but the concept is not restricted to that person.
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Possibility of multiple application, not an actual count
Universal and Particular — Definitions and Practical Classification
The phrase 'can apply' is decisive. A universal need not have many currently visible instances. What matters is whether the meaning itself admits application to more than one individual.
Imagine a room with only one student. 'Student' remains universal because someone else could also fit that meaning.
There is one individual in the room, but the concept is not restricted to that person.