What is the meaning of Numerus?

(grammatical) number

antilogarithm (the ${\displaystyle x}$ in ${\displaystyle a^{y}=x\Leftrightarrow \log _{a}(x)=y}$)

number

Roman military unit

collection, quantity

rank, position

time, rhythm

number

number (the state of being singular or plural as shown by inflection)

Source: wiktionary.org