to control or direct (something) according to rules
to bring order, method, or uniformity to (something)
to fix or adjust the time, amount, degree, or rate of (something)
regulating the pressure of a tyre
regulable adj
regulative /-lətiv/ adj
regulator noun
regulatory /-lət(ə)ri, -ʹlayt(ə)ri/ adj
[late Latin regulatus, past part. of regulare, from Latin regula rule]