When a doctor orders laboratory tests, like blood tests for disease or for nutritional status, the doctor is the referring doctor: he refers the patient to the lab. In medicine, it approximately means sends, because the doctor is sending the patient to the lab, or other doctor, or . . .
Definitions for still waters run deep. Here are all the possible meanings and translations of the word still waters run deep. Wiktionary(0.00 / 0 votes)Rate this definition: still waters run deep(Proverb) A person with a calm appearance has, or may have, considerable inner emotion, character, or intellect.
The idiom, water under the bridge is akin to another expression What's done is done, which means it is too late and pointless to change the past, too much water has flowed; i.e. time stands still for no one.